* Check if action is assigned before calling update on it

rtl/objpas/classes/action.inc

@@ -79,7 +79,8 @@ end;
 
 function TBasicActionLink.Update: Boolean;
 begin
-  Result := FAction.Update;
+  if Assigned(Faction) then
+    Result := FAction.Update;
 end;
 
 {****************************************************************************}