diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java
index 5ce7fea59..3f427d3ed 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/context/BaseWorkerContext.java
@@ -1375,7 +1375,7 @@ public abstract class BaseWorkerContext extends I18nBase implements IWorkerConte
 
   @Override
   public boolean isNoTerminologyServer() {
-    return noTerminologyServer;
+    return noTerminologyServer || txClient == null;
   }
 
   public void setNoTerminologyServer(boolean noTerminologyServer) {
diff --git a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/Element.java b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/Element.java
index 30ddff114..07c81b5d1 100644
--- a/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/Element.java
+++ b/org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/model/Element.java
@@ -427,6 +427,8 @@ public abstract class Element extends Base implements IBaseHasExtensions, IBaseE
       return null; 
     if (ext.size() > 1) 
       throw new FHIRException("Multiple matching extensions found for extension '"+theUrl+"'");
+    if (!ext.get(0).hasValue())
+      return null;
     if (!ext.get(0).getValue().isPrimitive())
       throw new FHIRException("Extension '"+theUrl+"' could not be converted to a string");
     return ext.get(0).getValue().primitiveValue();
diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java
index 6dd459541..d5a392059 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java
@@ -20,6 +20,7 @@ import org.hl7.fhir.r5.elementmodel.Element;
 import org.hl7.fhir.r5.elementmodel.Manager;
 import org.hl7.fhir.r5.elementmodel.Manager.FhirFormat;
 import org.hl7.fhir.r5.formats.IParser.OutputStyle;
+import org.hl7.fhir.r5.model.Base;
 import org.hl7.fhir.r5.model.Coding;
 import org.hl7.fhir.r5.model.ElementDefinition;
 import org.hl7.fhir.r5.model.ExpressionNode;
@@ -165,7 +166,10 @@ public class StructureDefinitionValidator extends BaseValidator {
       }
       String tc = type.getChildValue("code");
       if (type.hasExtension(ToolingExtensions.EXT_FHIR_TYPE)) {
-        tc = type.getExtensionValue(ToolingExtensions.EXT_FHIR_TYPE).primitiveValue();
+        Base tcv = type.getExtensionValue(ToolingExtensions.EXT_FHIR_TYPE);
+        if (tcv != null) {
+          tc = tcv.primitiveValue();
+        }
       }
       if (Utilities.noString(tc) && type.hasChild("code")) {
         if (VersionUtilities.isR4Plus(context.getVersion())) {