Problem with JCO maintainance

Dear Gurus,

We're facing problem with JCO maintainance, when I tried to create JCo, the message has been thrown as:

"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()"

The SSO is configured.

Is there anything we have to check or need to be done? Please advice.

Thanks you,

Khiem Nguyen.