Description of problem:
When you are assigning permissions to complement of some role (e.g. prohibit something to all roles except to role admin) the role is not assigned, because NullPointerException is thrown. Observe an example with steps to reproduce in the video.

Version-Release number of selected component (if applicable):
BPMS 6.0.1 ER1

How reproducible:
Always

Steps to Reproduce:
1. Try to assign some permission with "reverse" checkbox under role select checked

Actual results:
The permission is not assigned and NPE appears in the server.log

Expected results:
The reverse permission added successfully.b