Some permissions lacking to create proxy

When testing https://foliotest.testrail.io/index.php?/tests/view/16086, the user with the 3 user permissions related to creating and viewing proxies gets an error message.

Steps to Reproduce:
1. Log into the bugfest-goldenrod.folio.ebsco.com as user Patty Proxy (user name Proxy password Eight8**) The user has Check out circulating items, Check in, and 3 user permissions: Can create, edit and remove proxies, can view proxies assigned to users, can view user profile.
2. Click an active user record
3. Select the Edit action
4. Add a sponsor to the record
5. Save and close
Expected: Should save without error
Actual results:
Error saving the record (see attached screencast - you only need to watch up until 1:15).

Additional info:

• If you click the error away, it saves without issue.
• This only seems to happen the first time you edit a user and add a sponsor. I couldn't repro after the first time, even after clearing cache

Note in test that Mark Arnold has diagnosed that some backend permissions are missing.