When document is already being editted by another user, there is no proper error message but nothing happens in the cms

It is correct that another user cannot edit the document, because another user is already editting it. Though, a proper frontend message should be given instead of nothing happening

stacktrace:

12.06.2008 17:27:04 INFO [org.hippoecm.repository.decorating.WorkflowManagerImpl$WorkflowInvocationHandler.invoke():474] AUDIT workflow invocation b363e8be-2ec7-4f62-8ba0-2f9c7a335b17.org.hippoecm.repository.reviewedactions.FullReviewedActionsWorkflowImpl.obtainEditableInstance() -> org.hippoecm.repository.api.WorkflowException
org.hippoecm.repository.api.WorkflowException: document already being edited
at org.hippoecm.repository.reviewedactions.BasicReviewedActionsWorkflowImpl.obtainEditableInstance(BasicReviewedActionsWorkflowImpl.java:55)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.hippoecm.repository.decorating.WorkflowManagerImpl$WorkflowInvocationHandler.invoke(WorkflowManagerImpl.java:421)
at $Proxy3.obtainEditableInstance(Unknown Source)
at org.hippoecm.frontend.plugins.reviewedactions.FullReviewedActionsWorkflowPlugin$1.execute(FullReviewedActionsWorkflowPlugin.java:61)