Content Administrator > Maintain / Create Jco Destination NullPointerExc

Hello!

When I try maintain or create Jco Destination in Web Dynpro Content Administrator I get the following Exception page:

java.lang.NullPointerException: while trying to invoke the method java.lang.String.equals(java.lang.Object) of an object returned from com.sap.lcr.api.sapmodel.SAP_JCODestination.getUserHandling()

When I click "Check SLD Connection" -> Test Connection it says:

So where is the Problem?
I also tried to restart the server, but with no success.

Thanks for your help and regards