OG permission listboxes empty

Prerequisites:

• be a group admin

Steps to reproduce:

1. After login go to the Member listing page (https://localize-7.staging.devdrupal.org/group/node/158/admin/people)
2. Tick the checkbox in the row of any member
3. Choose "Modify OG user roles" option from the dropdown list in the Operations section. Click Execute button.
4. The two multi-line listbox appears empty.

Btw, if you click into any of listboxes to act like if you would choose an item, then continue with "Next", the process seems to run through without problem. However assumably it does nothing, because no any parameter was chosen from the listboxes.

Please check my other issue #2539356: Permission names not shown beside checkboxes which seems quite related to this one.