SAP Message 5W366 - Forwarding to &1 &2 is not possible

Diagnosis
Work items can only be forwarded to 'possible agents' of their tasks.
Exception: the task in question is a general task, and theGeneral forwarding not allowed indicator has notbeen set. If this is the case, the work item can be forwarded to allusers in the system, but not to other recipients such as positions ororganizational units. Such recipients must always be possible agents ofthe task.