diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 1c90c7f4d1..e4f1844aa1 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -57,7 +57,7 @@ jobs:
   spelling:
     name: Docs Spelling Checks
     runs-on: ubuntu-latest
-    timeout-minutes: 1
+    timeout-minutes: 2
     steps:
       - uses: actions/checkout@v4
       - name: Check Spelling
diff --git a/bin/test_schema b/bin/test_schema
index 19f6c3a40f..8d733e8309 100755
--- a/bin/test_schema
+++ b/bin/test_schema
@@ -15,7 +15,7 @@ upgrade=
 schemadir=schema
 testdir=tests/schemas/
 outroot=out
-rm -rf outroot/tests
+rm -rf $outroot/tests
 
 while getopts "d:s:fnu" opt; do
     case $opt in
@@ -69,7 +69,7 @@ for subset in $subsets; do
         reldir=$(realpath --relative-to $schemadir $testdir)
         reltest=$reldir:$subset
     fi
-    cmd="$javarun -a $schemaname $upgrade -f $reltest"
+    cmd="$javarun -n -a $schemaname $upgrade -f $reltest"
     echo $cmd
     (cd $schemadir; $cmd) || true
 
diff --git a/common/src/main/java/com/google/daq/mqtt/util/ExceptionList.java b/common/src/main/java/com/google/daq/mqtt/util/ExceptionList.java
new file mode 100644
index 0000000000..c37fccdfa6
--- /dev/null
+++ b/common/src/main/java/com/google/daq/mqtt/util/ExceptionList.java
@@ -0,0 +1,15 @@
+package com.google.daq.mqtt.util;
+
+import static java.lang.String.format;
+
+import java.util.List;
+
+public class ExceptionList extends RuntimeException {
+
+  private final List<Exception> list;
+
+  public ExceptionList(List<Exception> list) {
+    super(format("List of %d exceptions", list.size()));
+    this.list = list;
+  }
+}
diff --git a/common/src/main/java/com/google/udmi/util/CommandLineProcessor.java b/common/src/main/java/com/google/udmi/util/CommandLineProcessor.java
index 8608ef4b2b..621f0a8980 100644
--- a/common/src/main/java/com/google/udmi/util/CommandLineProcessor.java
+++ b/common/src/main/java/com/google/udmi/util/CommandLineProcessor.java
@@ -1,6 +1,7 @@
 package com.google.udmi.util;
 
 import static com.google.common.base.Preconditions.checkState;
+import static com.google.udmi.util.GeneralUtils.friendlyStackTrace;
 import static com.google.udmi.util.GeneralUtils.ifNotNullThen;
 import static java.lang.String.CASE_INSENSITIVE_ORDER;
 import static java.util.Objects.nonNull;
@@ -119,7 +120,7 @@ public List<String> processArgs(List<String> argList) {
       }
       return null;
     } catch (Exception e) {
-      showUsage(e.getMessage());
+      showUsage(friendlyStackTrace(e));
       return null;
     }
   }
diff --git a/etc/validator.out b/etc/validator.out
index bc4884bd22..4d4320d94d 100644
--- a/etc/validator.out
+++ b/etc/validator.out
@@ -66,7 +66,7 @@ sites/udmi_site_model/out/devices/AHU-1/events_pointset.out
   "sub_type" : "events",
   "status" : {
     "message" : "Multiple validation errors",
-    "detail" : "Timestamp skew REDACTED_DURATION (REDACTED_TIMESTAMP to REDACTED_TIMESTAMP) exceeds REDACTED_DURATION threshold; While converting to json node: 1 schema violations found",
+    "detail" : "Timestamp skew REDACTED_DURATION (REDACTED_TIMESTAMP to REDACTED_TIMESTAMP) exceeds REDACTED_DURATION threshold; 1 schema violations found",
     "category" : "validation.device.multiple",
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
@@ -82,8 +82,8 @@ sites/udmi_site_model/out/devices/AHU-1/events_pointset.out
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
   }, {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "events_pointset: While converting to json node: 1 schema violations found REDACTED_ERROR; 1 schema violations found; object instance has properties which are not allowed by the schema: [\"extraField\"]",
+    "message" : "1 schema violations found",
+    "detail" : "events_pointset: 1 schema violations found; object instance has properties which are not allowed by the schema: [\"extraField\"]",
     "category" : "validation.device.schema",
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
@@ -145,7 +145,7 @@ sites/udmi_site_model/out/devices/AHU-1/state.out
   "sub_type" : "state",
   "status" : {
     "message" : "Multiple validation errors",
-    "detail" : "Timestamp skew REDACTED_DURATION (REDACTED_TIMESTAMP to REDACTED_TIMESTAMP) exceeds REDACTED_DURATION threshold; While converting to json node: 1 schema violations found",
+    "detail" : "Timestamp skew REDACTED_DURATION (REDACTED_TIMESTAMP to REDACTED_TIMESTAMP) exceeds REDACTED_DURATION threshold; 1 schema violations found",
     "category" : "validation.device.multiple",
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
@@ -157,8 +157,8 @@ sites/udmi_site_model/out/devices/AHU-1/state.out
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
   }, {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_update: While converting to json node: 1 schema violations found REDACTED_ERROR; 1 schema violations found; /system: object instance has properties which are not allowed by the schema: [\"extraField\"]",
+    "message" : "1 schema violations found",
+    "detail" : "state_update: 1 schema violations found; /system: object instance has properties which are not allowed by the schema: [\"extraField\"]",
     "category" : "validation.device.schema",
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
@@ -411,15 +411,15 @@ sites/udmi_site_model/out/devices/GAT-123/events_discovery.out
   "sub_folder" : "discovery",
   "sub_type" : "events",
   "status" : {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "events_discovery: While converting to json node: 1 schema violations found REDACTED_ERROR; 1 schema violations found; object has missing required properties ([\"scan_family\"])",
+    "message" : "1 schema violations found",
+    "detail" : "events_discovery: 1 schema violations found; object has missing required properties ([\"scan_family\"])",
     "category" : "validation.device.schema",
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "events_discovery: While converting to json node: 1 schema violations found REDACTED_ERROR; 1 schema violations found; object has missing required properties ([\"scan_family\"])",
+    "message" : "1 schema violations found",
+    "detail" : "events_discovery: 1 schema violations found; object has missing required properties ([\"scan_family\"])",
     "category" : "validation.device.schema",
     "timestamp" : "REDACTED_TIMESTAMP",
     "level" : 500
diff --git a/tests/schemas/events_discovery/discovery_node.json b/tests/schemas/events_discovery/discovery_node.json
new file mode 100644
index 0000000000..45325eeede
--- /dev/null
+++ b/tests/schemas/events_discovery/discovery_node.json
@@ -0,0 +1,245 @@
+{
+  "timestamp": "2024-11-21T12:10:46Z",
+  "version": "1.5.1",
+  "generation": "2024-11-21T12:09:30Z",
+  "scan_family": "bacnet",
+  "scan_addr": "10117",
+  "event_no": 9,
+  "families": {
+    "ipv4": {
+      "addr": "192.168.1.131"
+    }
+  },
+  "refs": {
+    "AI:1": {
+      "name": "FCU_1180 Room Temp",
+      "possible_values": [],
+      "units": "degreesCelsius",
+      "description": "",
+      "ancillary": {
+        "present_value": 20.488115310668945
+      }
+    },
+    "AI:2": {
+      "name": "FCU_1180 Supply Air Temp",
+      "possible_values": [],
+      "units": "degreesCelsius",
+      "description": "",
+      "ancillary": {
+        "present_value": 20.14183235168457
+      }
+    },
+    "AO:1": {
+      "name": "FCU_1180 Heating Valve",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 0.0
+      }
+    },
+    "AO:2": {
+      "name": "FCU_1180 Cooling Valve",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 0.0
+      }
+    },
+    "AO:3": {
+      "name": "FCU_1180 Fan Speed",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 70.0
+      }
+    },
+    "AV:1": {
+      "name": "FCU_1180 Setpoint",
+      "possible_values": [],
+      "units": "degreesCelsius",
+      "description": "",
+      "ancillary": {
+        "present_value": 20.0
+      }
+    },
+    "AV:2": {
+      "name": "FCU_1180 Min Fan Speed",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 20.0
+      }
+    },
+    "AV:3": {
+      "name": "FCU_1180 Max Fan Speed",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 100.0
+      }
+    },
+    "AV:4": {
+      "name": "FCU_1180 Design Fan Speed",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 70.0
+      }
+    },
+    "AV:5": {
+      "name": "FCU_1180 Design Heating Valve Position",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 75.0
+      }
+    },
+    "AV:6": {
+      "name": "FCU_1180 Design Cooling Valve Position",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 67.0
+      }
+    },
+    "AV:7": {
+      "name": "FCU_1180 Mode_Mimic",
+      "possible_values": [],
+      "units": "noUnits",
+      "description": "",
+      "ancillary": {
+        "present_value": 1.0
+      }
+    },
+    "AV:9991": {
+      "name": "FCU_1180 Comfort KPI Score (Live)",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 69.89265441894531
+      }
+    },
+    "AV:9992": {
+      "name": "FCU_1180 Comfort KPI Score (Yesterday)",
+      "possible_values": [],
+      "units": "percent",
+      "description": "",
+      "ancillary": {
+        "present_value": 69.99639129638672
+      }
+    },
+    "BI:3": {
+      "name": "FCU_1180 Fan Status",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "active"
+      }
+    },
+    "BI:4": {
+      "name": "FCU_1180 Occupancy",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "active"
+      }
+    },
+    "BO:4": {
+      "name": "FCU_1180 Enable",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "active"
+      }
+    },
+    "BV:1": {
+      "name": "FCU_1180 BMS Remote",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "active"
+      }
+    },
+    "BV:2": {
+      "name": "FCU_1180 FCU Run Status",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "active"
+      }
+    },
+    "BV:9991": {
+      "name": "FCU_1180 Within Bounds",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "active"
+      }
+    },
+    "MSV:1": {
+      "name": "FCU_1180 Mode",
+      "possible_values": [
+        "Auto_",
+        "On_",
+        "Off_",
+        "Flushing_",
+        "Commissioning_"
+      ],
+      "description": "",
+      "ancillary": {
+        "present_value": 1
+      }
+    },
+    "LP:1": {
+      "name": "FCU_101 Valve Control Loop",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": 50.0
+      }
+    },
+    "LP:2": {
+      "name": "FCU_101 Fan Control Loop",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": 50.0
+      }
+    },
+    "CSV:1": {
+      "name": "Google Cloud IoT Gateway Configuration",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "{\n  \"hostName\": \"mqtt.bos.goog\",\n  \"tcpPort\": 8883,\n  \"location\": \"us-central1\",\n  \"project\": \"bos-platform-testing\",\n  \"registry\": \"UK-LON-GLAB\",\n  \"device\": \"DDC-17\"\n}"
+      }
+    },
+    "CSV:1000001": {
+      "name": "BLE PIN",
+      "possible_values": [],
+      "description": "",
+      "ancillary": {
+        "present_value": "800700"
+      }
+    }
+  },
+  "system": {
+    "serial_no": "141557/0009",
+    "ancillary": {
+      "name": "DDC-17"
+    },
+    "hardware": {
+      "make": "Delta Controls Inc.",
+      "model": "Red5-PLUS-1180"
+    }
+  }
+}
diff --git a/tests/schemas/events_discovery/discovery_node.out b/tests/schemas/events_discovery/discovery_node.out
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/schemas/events_discovery/node.out b/tests/schemas/events_discovery/node.out
index ba111b3d96..98fe9b373a 100644
--- a/tests/schemas/events_discovery/node.out
+++ b/tests/schemas/events_discovery/node.out
@@ -1,2 +1,2 @@
 1 schema violations found
-  /system: object instance has properties which are not allowed by the schema: ["software"]
\ No newline at end of file
+  /system: object instance has properties which are not allowed by the schema: ["software"]
diff --git a/tests/traces/simple/expected/devices/AHU-22/events_pointset.out b/tests/traces/simple/expected/devices/AHU-22/events_pointset.out
index 88f68e21a2..1806aafde7 100644
--- a/tests/traces/simple/expected/devices/AHU-22/events_pointset.out
+++ b/tests/traces/simple/expected/devices/AHU-22/events_pointset.out
@@ -4,8 +4,8 @@
   "sub_folder" : "pointset",
   "sub_type" : "events",
   "status" : {
-    "message" : "While converting to json node: 2 schema violations found",
-    "detail" : "events_pointset: While converting to json node: 2 schema violations found @Validator.validateMessage(REDACTED); 2 schema violations found; object instance has properties which are not allowed by the schema: [\"yesvalue\"]; object has missing required properties ([\"version\"])",
+    "message" : "2 schema violations found",
+    "detail" : "events_pointset: 2 schema violations found; object instance has properties which are not allowed by the schema: [\"yesvalue\"]; object has missing required properties ([\"version\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
@@ -15,8 +15,8 @@
     "extra" : [ ]
   },
   "errors" : [ {
-    "message" : "While converting to json node: 2 schema violations found",
-    "detail" : "events_pointset: While converting to json node: 2 schema violations found @Validator.validateMessage(REDACTED); 2 schema violations found; object instance has properties which are not allowed by the schema: [\"yesvalue\"]; object has missing required properties ([\"version\"])",
+    "message" : "2 schema violations found",
+    "detail" : "events_pointset: 2 schema violations found; object instance has properties which are not allowed by the schema: [\"yesvalue\"]; object has missing required properties ([\"version\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/simple/expected/devices/SNS-4/events_pointset.out b/tests/traces/simple/expected/devices/SNS-4/events_pointset.out
index ae6aa7735e..bc6ade3ecc 100644
--- a/tests/traces/simple/expected/devices/SNS-4/events_pointset.out
+++ b/tests/traces/simple/expected/devices/SNS-4/events_pointset.out
@@ -5,7 +5,7 @@
   "sub_type" : "events",
   "status" : {
     "message" : "Multiple validation errors",
-    "detail" : "While converting to json node: 1 schema violations found; Device has extra points: rocket_count, triangulating_axis_y",
+    "detail" : "1 schema violations found; Device has extra points: rocket_count, triangulating_axis_y",
     "category" : "validation.device.multiple",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
@@ -15,8 +15,8 @@
     "extra" : [ "rocket_count", "triangulating_axis_y" ]
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "events_pointset: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; object instance has properties which are not allowed by the schema: [\"monkey\"]",
+    "message" : "1 schema violations found",
+    "detail" : "events_pointset: 1 schema violations found; object instance has properties which are not allowed by the schema: [\"monkey\"]",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/simple/expected/devices/SNS-4/events_system.out b/tests/traces/simple/expected/devices/SNS-4/events_system.out
index 6c5c8c1f7f..b007b15d45 100644
--- a/tests/traces/simple/expected/devices/SNS-4/events_system.out
+++ b/tests/traces/simple/expected/devices/SNS-4/events_system.out
@@ -4,15 +4,15 @@
   "sub_folder" : "system",
   "sub_type" : "events",
   "status" : {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "events_system: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /logentries/0/category: instance entry category not recognized",
+    "message" : "1 schema violations found",
+    "detail" : "events_system: 1 schema violations found; /logentries/0/category: instance entry category not recognized",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "events_system: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /logentries/0/category: instance entry category not recognized",
+    "message" : "1 schema violations found",
+    "detail" : "events_system: 1 schema violations found; /logentries/0/category: instance entry category not recognized",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/simple/expected/validation_report.json b/tests/traces/simple/expected/validation_report.json
index 73ab4b9b83..dfa095c54e 100644
--- a/tests/traces/simple/expected/validation_report.json
+++ b/tests/traces/simple/expected/validation_report.json
@@ -25,8 +25,8 @@
     "AHU-22" : {
       "last_seen" : "1999-10-20T01:02:03Z",
       "status" : {
-        "message" : "While converting to json node: 2 schema violations found",
-        "detail" : "events_pointset: While converting to json node: 2 schema violations found @Validator.validateMessage(REDACTED); 2 schema violations found; object instance has properties which are not allowed by the schema: [\"yesvalue\"]; object has missing required properties ([\"version\"])",
+        "message" : "2 schema violations found",
+        "detail" : "events_pointset: 2 schema violations found; object instance has properties which are not allowed by the schema: [\"yesvalue\"]; object has missing required properties ([\"version\"])",
         "category" : "validation.device.schema",
         "timestamp" : "1999-10-20T01:02:03Z",
         "level" : 500
@@ -46,7 +46,7 @@
       "last_seen" : "1999-10-20T01:02:03Z",
       "status" : {
         "message" : "Multiple validation errors",
-        "detail" : "While converting to json node: 1 schema violations found; Device has extra points: rocket_count, triangulating_axis_y; Unexpected character ('{' (code 123)): was expecting double-quote to start field name\n at [Source: (File), line: 1, column: 3]; While converting to json node: 1 schema violations found",
+        "detail" : "1 schema violations found; Device has extra points: rocket_count, triangulating_axis_y; Unexpected character ('{' (code 123)): was expecting double-quote to start field name\n at [Source: (File), line: 1, column: 3]; 1 schema violations found",
         "category" : "validation.device.multiple",
         "timestamp" : "1999-10-20T01:02:03Z",
         "level" : 500
diff --git a/tests/traces/upgrade/expected/devices/AHU-1/state.out b/tests/traces/upgrade/expected/devices/AHU-1/state.out
index 1bd549ce5d..82ae93dc82 100644
--- a/tests/traces/upgrade/expected/devices/AHU-1/state.out
+++ b/tests/traces/upgrade/expected/devices/AHU-1/state.out
@@ -5,14 +5,14 @@
   "sub_type" : "state",
   "status" : {
     "message" : "Multiple validation errors",
-    "detail" : "While converting to json node: 1 schema violations found; missing pointset subblock",
+    "detail" : "1 schema violations found; missing pointset subblock",
     "category" : "validation.device.multiple",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_update: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
+    "message" : "1 schema violations found",
+    "detail" : "state_update: 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/upgrade/expected/devices/AHU-1/state_system.out b/tests/traces/upgrade/expected/devices/AHU-1/state_system.out
index 1ad02b544f..4a74512835 100644
--- a/tests/traces/upgrade/expected/devices/AHU-1/state_system.out
+++ b/tests/traces/upgrade/expected/devices/AHU-1/state_system.out
@@ -4,15 +4,15 @@
   "sub_folder" : "system",
   "sub_type" : "state",
   "status" : {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_system: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; object has missing required properties ([\"serial_no\"])",
+    "message" : "1 schema violations found",
+    "detail" : "state_system: 1 schema violations found; object has missing required properties ([\"serial_no\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_system: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; object has missing required properties ([\"serial_no\"])",
+    "message" : "1 schema violations found",
+    "detail" : "state_system: 1 schema violations found; object has missing required properties ([\"serial_no\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/upgrade/expected/devices/AHU-22/state.out b/tests/traces/upgrade/expected/devices/AHU-22/state.out
index 1bd549ce5d..82ae93dc82 100644
--- a/tests/traces/upgrade/expected/devices/AHU-22/state.out
+++ b/tests/traces/upgrade/expected/devices/AHU-22/state.out
@@ -5,14 +5,14 @@
   "sub_type" : "state",
   "status" : {
     "message" : "Multiple validation errors",
-    "detail" : "While converting to json node: 1 schema violations found; missing pointset subblock",
+    "detail" : "1 schema violations found; missing pointset subblock",
     "category" : "validation.device.multiple",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_update: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
+    "message" : "1 schema violations found",
+    "detail" : "state_update: 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/upgrade/expected/devices/NON-1/state.out b/tests/traces/upgrade/expected/devices/NON-1/state.out
index caa8884df0..4c65baed52 100644
--- a/tests/traces/upgrade/expected/devices/NON-1/state.out
+++ b/tests/traces/upgrade/expected/devices/NON-1/state.out
@@ -4,15 +4,15 @@
   "sub_folder" : "update",
   "sub_type" : "state",
   "status" : {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_update: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
+    "message" : "1 schema violations found",
+    "detail" : "state_update: 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
   },
   "errors" : [ {
-    "message" : "While converting to json node: 1 schema violations found",
-    "detail" : "state_update: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
+    "message" : "1 schema violations found",
+    "detail" : "state_update: 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
     "category" : "validation.device.schema",
     "timestamp" : "1999-10-20T01:02:03Z",
     "level" : 500
diff --git a/tests/traces/upgrade/expected/validation_report.json b/tests/traces/upgrade/expected/validation_report.json
index c6905a1986..7c4656ff83 100644
--- a/tests/traces/upgrade/expected/validation_report.json
+++ b/tests/traces/upgrade/expected/validation_report.json
@@ -17,7 +17,7 @@
       "last_seen" : "1999-10-20T01:02:03Z",
       "status" : {
         "message" : "Multiple validation errors",
-        "detail" : "While converting to json node: 1 schema violations found; missing pointset subblock; While converting to json node: 1 schema violations found",
+        "detail" : "1 schema violations found; missing pointset subblock; 1 schema violations found",
         "category" : "validation.device.multiple",
         "timestamp" : "1999-10-20T01:02:03Z",
         "level" : 500
@@ -27,7 +27,7 @@
       "last_seen" : "1999-10-20T01:02:03Z",
       "status" : {
         "message" : "Multiple validation errors",
-        "detail" : "While converting to json node: 1 schema violations found; missing pointset subblock",
+        "detail" : "1 schema violations found; missing pointset subblock",
         "category" : "validation.device.multiple",
         "timestamp" : "1999-10-20T01:02:03Z",
         "level" : 500
@@ -36,8 +36,8 @@
     "NON-1" : {
       "last_seen" : "1999-10-20T01:02:03Z",
       "status" : {
-        "message" : "While converting to json node: 1 schema violations found",
-        "detail" : "state_update: While converting to json node: 1 schema violations found @Validator.validateMessage(REDACTED); 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
+        "message" : "1 schema violations found",
+        "detail" : "state_update: 1 schema violations found; /system: object has missing required properties ([\"serial_no\"])",
         "category" : "validation.device.extra",
         "timestamp" : "1999-10-20T01:02:03Z",
         "level" : 400
diff --git a/validator/.idea/runConfigurations/Schema_Tester.xml b/validator/.idea/runConfigurations/Schema_Tester.xml
new file mode 100644
index 0000000000..bfff9219ec
--- /dev/null
+++ b/validator/.idea/runConfigurations/Schema_Tester.xml
@@ -0,0 +1,11 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Schema Tester" type="Application" factoryName="Application">
+    <option name="MAIN_CLASS_NAME" value="com.google.daq.mqtt.validator.SchemaTester" />
+    <module name="validator" />
+    <option name="PROGRAM_PARAMETERS" value="-n -a metadata.json -f ../tests/schemas:metadata" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/../schema" />
+    <method v="2">
+      <option name="Make" enabled="true" />
+    </method>
+  </configuration>
+</component>
\ No newline at end of file
diff --git a/validator/.idea/runConfigurations/Test_Trace_Simple.xml b/validator/.idea/runConfigurations/Test_Trace_Simple.xml
new file mode 100644
index 0000000000..fc7dadc5dc
--- /dev/null
+++ b/validator/.idea/runConfigurations/Test_Trace_Simple.xml
@@ -0,0 +1,11 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Test Trace Simple" type="Application" factoryName="Application">
+    <option name="MAIN_CLASS_NAME" value="com.google.daq.mqtt.validator.SchemaTester" />
+    <module name="validator" />
+    <option name="PROGRAM_PARAMETERS" value="-p -- -s sites/udmi_site_model -r tests/traces/simple --" />
+    <option name="WORKING_DIRECTORY" value="$PROJECT_DIR$/../" />
+    <method v="2">
+      <option name="Make" enabled="true" />
+    </method>
+  </configuration>
+</component>
\ No newline at end of file
diff --git a/validator/src/main/java/com/google/daq/mqtt/validator/ReportingDevice.java b/validator/src/main/java/com/google/daq/mqtt/validator/ReportingDevice.java
index fefa01b96f..ba67641497 100644
--- a/validator/src/main/java/com/google/daq/mqtt/validator/ReportingDevice.java
+++ b/validator/src/main/java/com/google/daq/mqtt/validator/ReportingDevice.java
@@ -2,10 +2,12 @@
 
 import static com.google.udmi.util.Common.SUBFOLDER_PROPERTY_KEY;
 import static com.google.udmi.util.Common.SUBTYPE_PROPERTY_KEY;
+import static java.lang.String.format;
 import static java.util.Optional.ofNullable;
 import static org.junit.Assert.assertTrue;
 
 import com.google.common.base.Joiner;
+import com.google.daq.mqtt.util.ExceptionList;
 import com.google.daq.mqtt.util.ValidationException;
 import com.google.udmi.util.Common;
 import java.time.Instant;
@@ -39,6 +41,7 @@ public class ReportingDevice {
   private static Date mockNow;
   private final String deviceId;
   private final List<Entry> entries = new ArrayList<>();
+  private final Map<Entry, Exception> entryExceptions = new HashMap<>();
   private final List<Entry> messageEntries = new ArrayList<>();
   private final Map<String, Date> messageMarks = new HashMap<>();
   private Date lastSeen = new Date(0); // Always defined, just start a long time ago!
@@ -228,7 +231,7 @@ public void updateLastSeen(Date timestamp) {
 
   private Exception pointValidationError(String description, Set<String> points) {
     return new ValidationException(
-        String.format("Device has %s: %s", description, Joiner.on(", ").join(points)));
+        format("Device has %s: %s", description, Joiner.on(", ").join(points)));
   }
 
   private void addEntry(Entry entry) {
@@ -250,16 +253,18 @@ void addError(Exception error, Map<String, String> attributes, String category)
     String subFolder = attributes.get(SUBFOLDER_PROPERTY_KEY);
     String subType = attributes.get(SUBTYPE_PROPERTY_KEY);
     addError(error, category,
-        String.format("%s: %s", typeFolderPairKey(subType, subFolder),
+        format("%s: %s", typeFolderPairKey(subType, subFolder),
             Common.getExceptionDetail(error, this.getClass(), ReportingDevice::validationMessage)));
   }
 
   void addError(Exception error, String category, String detail) {
-    addEntry(makeEntry(error, category, detail));
+    Entry entry = makeEntry(error, category, detail);
+    entryExceptions.put(entry, error);
+    addEntry(entry);
   }
 
   public static String typeFolderPairKey(String subType, String subFolder) {
-    return String.format("%s_%s", ofNullable(subType).orElse(SubType.EVENTS.value()), subFolder);
+    return format("%s_%s", ofNullable(subType).orElse(SubType.EVENTS.value()), subFolder);
   }
 
   /**
@@ -344,6 +349,20 @@ public List<Entry> getMessageEntries() {
     return messageEntries;
   }
 
+  /**
+   * Check for errors and throw a fit if necessary.
+   */
+  public void throwIfFailure() {
+    if (!hasErrors()) {
+      return;
+    }
+    if (messageEntries.size() == 1) {
+      throw (RuntimeException) entryExceptions.get(messageEntries.get(0));
+    }
+    List<Exception> exceptions = entries.stream().map(entry -> entryExceptions.get(entry)).toList();
+    throw new ExceptionList(exceptions);
+  }
+
   /**
    * Encapsulation of metadata differences.
    */
diff --git a/validator/src/main/java/com/google/daq/mqtt/validator/Validator.java b/validator/src/main/java/com/google/daq/mqtt/validator/Validator.java
index 8e0f8f71e1..0bd335f7ae 100644
--- a/validator/src/main/java/com/google/daq/mqtt/validator/Validator.java
+++ b/validator/src/main/java/com/google/daq/mqtt/validator/Validator.java
@@ -43,7 +43,6 @@
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.JsonNode;
-import com.github.fge.jsonschema.core.exceptions.ProcessingException;
 import com.github.fge.jsonschema.core.load.configuration.LoadingConfiguration;
 import com.github.fge.jsonschema.core.load.download.URIDownloader;
 import com.github.fge.jsonschema.core.report.LogLevel;
@@ -186,8 +185,10 @@ public class Validator {
   private static final int TIMESTAMP_JITTER_SEC = 60;
   private static final String UDMI_CONFIG_JSON_FILE = "udmi_config.json";
   private static final String TOOL_NAME = "validator";
-  public static final String VALIDATOR_TOOL_NAME = "validator";
-  public static final String REGISTRY_DEVICE_DEFAULT = "_regsitry";
+  private static final String FAUX_DEVICE_ID = "TEST-97";
+  private static final String VALIDATOR_TOOL_NAME = "validator";
+  private static final String REGISTRY_DEVICE_DEFAULT = "_regsitry";
+  private static final String SCHEMA_NAME_KEY = "ignore_envelope";
   private long reportingDelaySec = DEFAULT_INTERVAL_SEC;
   private final CommandLineProcessor commandLineProcessor = new CommandLineProcessor(this);
   private final Map<String, ReportingDevice> reportingDevices = new TreeMap<>();
@@ -558,8 +559,8 @@ private Map<String, JsonSchema> getSchemaMap() {
       throw new RuntimeException("Missing schema for attribute validation: " + ENVELOPE_SCHEMA_ID);
     }
 
-    // Rename the metadata schema to model, which is how it's handled programmatically.
-    schemaMap.put("model", schemaMap.remove("metadata"));
+    // Copy the metadata schema to model, since sometimes it's referenced that way.
+    schemaMap.put("model", schemaMap.get("metadata"));
 
     return schemaMap;
   }
@@ -693,12 +694,9 @@ private void validateMessage(Object msgObject, Map<String, String> attributes) {
     }
   }
 
-  private void validateMessage(JsonSchema schema, Object message) {
-    try {
-      validateJsonNode(schema, OBJECT_MAPPER.valueToTree(message));
-    } catch (Exception e) {
-      throw new RuntimeException("While converting to json node: " + e.getMessage(), e);
-    }
+  private void validateMessage(JsonSchema schema, Object message) throws Exception {
+    ProcessingReport report = schema.validate(OBJECT_MAPPER.valueToTree(message), true);
+    ifTrueThen(!report.isSuccess(), () -> ifNotNullThrow(fromProcessingReport(report)));
   }
 
   private Instant getInstant(Object msgObject, Map<String, String> attributes) {
@@ -810,14 +808,18 @@ private boolean processExceptions(Map<String, String> attributes, String deviceI
    */
   public void validateDeviceMessage(ReportingDevice device, Map<String, Object> message,
       Map<String, String> attributes) {
-    String schemaName = messageSchema(attributes);
+    String schemaName = ofNullable(attributes.get(SCHEMA_NAME_KEY)).orElseGet(
+        () -> messageSchema(attributes));
     upgradeMessage(schemaName, message);
 
-    try {
-      validateMessage(schemaMap.get(ENVELOPE_SCHEMA_ID), (Object) attributes);
-    } catch (Exception e) {
-      outputLogger.error("Error validating attributes: " + friendlyStackTrace(e));
-      device.addError(e, attributes, Category.VALIDATION_DEVICE_RECEIVE);
+    // Assume the attributes know what they're doing when the schema name is provided explicitly.
+    if (!attributes.containsKey(SCHEMA_NAME_KEY)) {
+      try {
+        validateMessage(schemaMap.get(ENVELOPE_SCHEMA_ID), (Object) attributes);
+      } catch (Exception e) {
+        outputLogger.error("Error validating attributes: " + friendlyStackTrace(e));
+        device.addError(e, attributes, Category.VALIDATION_DEVICE_RECEIVE);
+      }
     }
 
     if (schemaMap.containsKey(schemaName)) {
@@ -1193,7 +1195,6 @@ private void validateFilesOutput(String targetSpec) {
     } catch (ExceptionMap processingException) {
       ErrorTree errorTree = ExceptionMap.format(processingException);
       errorTree.write(System.err);
-      throw processingException;
     }
   }
 
@@ -1253,7 +1254,9 @@ private void validateFile(
         outputStream.close();
         FileUtils.copyFile(inputFile, outputFile);
       }
-      validateJsonNode(schema, jsonNode);
+      ReportingDevice reportingDevice = new ReportingDevice(FAUX_DEVICE_ID);
+      validateDeviceMessage(reportingDevice, message, makeFileAttributes(schemaName));
+      reportingDevice.throwIfFailure();
       writeExceptionOutput(targetOut, null);
     } catch (Exception e) {
       writeExceptionOutput(targetOut, e);
@@ -1261,6 +1264,12 @@ private void validateFile(
     }
   }
 
+  private Map<String, String> makeFileAttributes(String schemaName) {
+    HashMap<String, String> attributes = new HashMap<>();
+    attributes.put(SCHEMA_NAME_KEY, schemaName);
+    return attributes;
+  }
+
   private void copyFileHeader(File inputFile, OutputStream outputFile) {
     try (Scanner scanner = new Scanner(inputFile)) {
       while (scanner.hasNextLine()) {
@@ -1304,11 +1313,6 @@ private void upgradeMessage(String schemaName, Map<String, Object> message) {
     message.putAll(objectMap);
   }
 
-  private void validateJsonNode(JsonSchema schema, JsonNode jsonNode) throws ProcessingException {
-    ProcessingReport report = schema.validate(jsonNode, true);
-    ifTrueThen(!report.isSuccess(), () -> ifNotNullThrow(fromProcessingReport(report)));
-  }
-
   private File getFullPath(String prefix, File targetFile) {
     return prefix == null ? targetFile : new File(new File(prefix), targetFile.getPath());
   }