diff --git a/imixs-workflow-core/src/main/java/org/imixs/workflow/WorkflowKernel.java b/imixs-workflow-core/src/main/java/org/imixs/workflow/WorkflowKernel.java
index 0870110ea..db8ca2748 100644
--- a/imixs-workflow-core/src/main/java/org/imixs/workflow/WorkflowKernel.java
+++ b/imixs-workflow-core/src/main/java/org/imixs/workflow/WorkflowKernel.java
@@ -544,7 +544,7 @@ private void executeSignalAdapters(ItemCollection documentResult, ItemCollection
 
 					} else {
 						throw new PluginException(WorkflowKernel.class.getSimpleName(), PLUGIN_ERROR,
-								"Abstract Adapter '" + adapterClass + "' can not be executed!");
+								"Abstract Adapter '" + adapterClass + "' can not be executed - use SignalAdapter or GenericAdapter instead!");
 						
 					}
 				}