diff --git a/Model/src/main/java/org/gusdb/wdk/model/user/UserCache.java b/Model/src/main/java/org/gusdb/wdk/model/user/UserCache.java
index 19aaca2ea..2d7239e5f 100644
--- a/Model/src/main/java/org/gusdb/wdk/model/user/UserCache.java
+++ b/Model/src/main/java/org/gusdb/wdk/model/user/UserCache.java
@@ -23,7 +23,7 @@ public UserCache(UserFactory userFactory) {
    */
   public UserCache(User user) {
     put(user.getUserId(), user);
-    _userFactory = null;
+    _userFactory = user.getWdkModel().getUserFactory();
   }
 
   public void loadUsersByIds(List<Long> userIds) {
@@ -41,13 +41,10 @@ public User get(Object id) {
       }
       Long userId = (Long)id;
       if (!containsKey(userId)) {
-        if (_userFactory != null) {
+        synchronized(this) {
           put(userId, _userFactory.getUserById(userId)
               .orElseThrow(() -> new WdkRuntimeException("User with ID " + userId + " does not exist.")));
         }
-        else {
-          throw new WdkRuntimeException("No-lookup cache does not contain the requested user (" + userId + ").");
-        }
       }
       return super.get(userId);
     }
diff --git a/Model/src/main/java/org/gusdb/wdk/model/user/UserFactory.java b/Model/src/main/java/org/gusdb/wdk/model/user/UserFactory.java
index fcd98ac64..5be064650 100644
--- a/Model/src/main/java/org/gusdb/wdk/model/user/UserFactory.java
+++ b/Model/src/main/java/org/gusdb/wdk/model/user/UserFactory.java
@@ -180,7 +180,18 @@ public void resetPassword(String loginName) throws InvalidUsernameOrEmailExcepti
   public Map<Long, User> getUsersById(List<Long> userIds) {
     // ensure a unique list
     userIds = new ArrayList<>(new HashSet<>(userIds));
-    return OAuthQuerier.getUsersById(_client, _config, userIds, json -> new BasicUser(_wdkModel, json));
+    Map<Long,User> userMap = OAuthQuerier.getUsersById(_client, _config, userIds, json -> new BasicUser(_wdkModel, json));
+    // FIXME: This is a temporary hack to account for guests created before the
+    //   implementation of bearer tokens who still have WDK steps/strats.  Eventually
+    //   these guests should be removed during regular maintenance cleanup; once all
+    //   guests created before spring 2024 are removed, this code can also be removed.
+    for (Long userId : userIds) {
+      if (userMap.get(userId) == null) {
+        // OAuth does not know about this user; trust that it is a guest
+        userMap.put(userId, new BasicUser(_wdkModel, userId, true, userId.toString(), userId.toString()));
+      }
+    }
+    return userMap;
   }
 
   public Map<String, User> getUsersByEmail(List<String> emails) {
diff --git a/Model/src/main/java/org/gusdb/wdk/model/user/UserPasswordEmailer.java b/Model/src/main/java/org/gusdb/wdk/model/user/UserPasswordEmailer.java
index 8806d2d42..8db094bfc 100644
--- a/Model/src/main/java/org/gusdb/wdk/model/user/UserPasswordEmailer.java
+++ b/Model/src/main/java/org/gusdb/wdk/model/user/UserPasswordEmailer.java
@@ -1,6 +1,5 @@
 package org.gusdb.wdk.model.user;
 
-import java.util.Optional;
 import java.util.regex.Matcher;
 
 import org.gusdb.wdk.model.Attachment;
diff --git a/Model/src/main/java/org/gusdb/wdk/model/user/UserReferenceFactory.java b/Model/src/main/java/org/gusdb/wdk/model/user/UserReferenceFactory.java
index 4b81ec6fe..d7f72f05c 100644
--- a/Model/src/main/java/org/gusdb/wdk/model/user/UserReferenceFactory.java
+++ b/Model/src/main/java/org/gusdb/wdk/model/user/UserReferenceFactory.java
@@ -1,6 +1,5 @@
 package org.gusdb.wdk.model.user;
 
-import java.sql.Timestamp;
 import java.sql.Types;
 import java.util.Date;
 import java.util.Optional;
diff --git a/Model/src/test/java/org/gusdb/wdk/model/fix/table/edaanalysis/plugins/VDIMigrationPluginTest.java b/Model/src/test/java/org/gusdb/wdk/model/fix/table/edaanalysis/plugins/VDIMigrationPluginTest.java
index b94a1f653..b68661501 100644
--- a/Model/src/test/java/org/gusdb/wdk/model/fix/table/edaanalysis/plugins/VDIMigrationPluginTest.java
+++ b/Model/src/test/java/org/gusdb/wdk/model/fix/table/edaanalysis/plugins/VDIMigrationPluginTest.java
@@ -1,6 +1,11 @@
 package org.gusdb.wdk.model.fix.table.edaanalysis.plugins;
 
-import org.gusdb.wdk.model.WdkModel;
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Objects;
+import java.util.Optional;
+
 import org.gusdb.wdk.model.fix.table.TableRowInterfaces;
 import org.gusdb.wdk.model.fix.table.edaanalysis.AnalysisRow;
 import org.json.JSONObject;
@@ -9,21 +14,14 @@
 import org.junit.Test;
 import org.mockito.Mockito;
 
-import java.io.File;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.Objects;
-import java.util.Optional;
-
 public class VDIMigrationPluginTest {
-  private WdkModel mockedModel;
+
   private ClassLoader classLoader;
   private VDIEntityIdRetriever retriever;
 
   @Before
   public void setup() {
     classLoader = getClass().getClassLoader();
-    mockedModel = Mockito.mock(WdkModel.class);
     retriever = Mockito.mock(VDIEntityIdRetriever.class);
   }