Errors about single step transformer being defined in a T-Engine were not being issued, because the baseUrl was set to "---" in the router.

engines/base/src/main/java/org/alfresco/transform/base/TransformController.java

@@ -97,7 +97,6 @@ import static org.springframework.http.MediaType.MULTIPART_FORM_DATA_VALUE;
 @Controller
 public class TransformController
 {
-
     private static final Logger logger = LoggerFactory.getLogger(TransformController.class);
 
     private static final String MODEL_TITLE = "title";

engines/base/src/main/java/org/alfresco/transform/base/registry/AbstractTransformConfigSource.java

@@ -36,7 +36,7 @@ public abstract class AbstractTransformConfigSource implements TransformConfigSo
     {
         this.sortOnName = sortOnName;
         this.readFrom = readFrom;
-        this.baseUrl = baseUrl == null ? "---" : baseUrl;
+        this.baseUrl = baseUrl;
     }
 
     @Override

engines/base/src/main/java/org/alfresco/transform/base/registry/TransformRegistry.java

@@ -225,7 +225,7 @@ public class TransformRegistry extends AbstractTransformRegistry
                     .map(name -> {
                         Origin<Transformer> transformerOrigin = transformerByNameMap.get(name);
                         String message = "  " + name + (transformerOrigin == null
-                            ? " -- unavailable: missing transform steps"
+                            ? " -- unavailable: see previous messages"
                             : isTRouter
                             ? ""
                             : TransformerType.valueOf(transformerOrigin.get()) == PIPELINE_TRANSFORMER