diff --git a/.gitignore b/.gitignore
index a9bbe77cba9..2cfed2b7f15 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@ __pycache__/
 
 # Distribution / packaging
 .Python
+.venv/
 env*/
 dbt_env/
 build/
diff --git a/core/dbt/parser/manifest.py b/core/dbt/parser/manifest.py
index a0cc49faa20..017ba02e678 100644
--- a/core/dbt/parser/manifest.py
+++ b/core/dbt/parser/manifest.py
@@ -19,6 +19,8 @@
 from itertools import chain
 import time
 
+import agate
+
 from dbt.context.manifest import generate_query_header_context
 from dbt.contracts.graph.semantic_manifest import SemanticManifest
 from dbt_common.events.base_types import EventLevel
@@ -157,12 +159,17 @@ def extended_msgpack_encoder(obj):
     elif type(obj) is datetime.datetime:
         datetime_bytes = msgpack.ExtType(2, obj.isoformat().encode())
         return datetime_bytes
+    elif isinstance(obj, agate.Table):
+        agate_bytes = msgpack.ExtType(3, "".encode())
+        return agate_bytes
 
     return obj
 
 
 def extended_mashumuro_decoder(data):
-    return msgpack.unpackb(data, ext_hook=extended_msgpack_decoder, raw=False)
+    return msgpack.unpackb(
+        data, ext_hook=extended_msgpack_decoder, raw=False, strict_map_key=False
+    )
 
 
 def extended_msgpack_decoder(code, data):
@@ -172,6 +179,8 @@ def extended_msgpack_decoder(code, data):
     elif code == 2:
         dt = datetime.datetime.fromisoformat(data.decode())
         return dt
+    elif code == 3:
+        return ""
     else:
         return msgpack.ExtType(code, data)