On stage-beta attempting to add permissions to a role causes the page to Something Went Wrong error.

Steps to reproduce:
1. login to c.stage.rh.com/beta
2. Select the cog in the masthead and go to "Identity & Access Management:
3. Select "Roles" under the User Access section
4. Create a new role
5. Search for and click on the newly created role in the roles table to go to that role's details page
6. Click the "Add permissions" button

Expected results:
1-5. -
6. The permissions modal should appear, and allow the user to add selected permissions.

Actual results:
1-5. -
6. The page crashes with a "something went wrong" error