Index: applications/editors/josm/plugins/comfort0/src/net/simon04/comfort0/EditLevel0LAction.java
===================================================================
--- applications/editors/josm/plugins/comfort0/src/net/simon04/comfort0/EditLevel0LAction.java	(revision 35620)
+++ applications/editors/josm/plugins/comfort0/src/net/simon04/comfort0/EditLevel0LAction.java	(revision 35621)
@@ -11,4 +11,5 @@
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -46,5 +47,5 @@
                 "theta",
                 tr("Edit the selected objects in an external editor in the Level0L format"),
-                null, false);
+                null, false, "EditLevel0LAction", true);
     }
 
@@ -56,4 +57,14 @@
             Logging.error(ex);
         }
+    }
+
+    @Override
+    protected void updateEnabledState() {
+        updateEnabledStateOnCurrentSelection(true);
+    }
+
+    @Override
+    protected void updateEnabledState(Collection<? extends OsmPrimitive> selection) {
+        setEnabled(selection != null && !selection.isEmpty());
     }