diff --git a/src/main/java/org/olat/core/gui/control/winmgr/AjaxController.java b/src/main/java/org/olat/core/gui/control/winmgr/AjaxController.java
index 7905860f6fb24e378cc5925d78b08b3293e819bf..f2f91cf0a5fb0d96a39c66acc90f49eb40761780 100644
--- a/src/main/java/org/olat/core/gui/control/winmgr/AjaxController.java
+++ b/src/main/java/org/olat/core/gui/control/winmgr/AjaxController.java
@@ -161,6 +161,7 @@ public class AjaxController extends DefaultController {
 						resource = new NothingChangedMediaResource();
 					}
 				} catch (CannotReplaceDOMFragmentException e) {
+					log.error("", e);
 					String timestampID = uureq.getTimestampID();
 					String reRenderUri = window.buildURIFor(window, timestampID, null);
 					Command rmrcom = CommandFactory.createParentRedirectTo(reRenderUri);