Deleted Group cannot be removed from a Role

Summary

Group cannot be removed from a role when it has been deleted.

Steps to Reproduce

1. Create a group.
2. Add the group to a role.
3. Delete the group.

1. Click "Remove" and confirm on the "People" tab where the group is associated with a role.

Expected Results

The group to role association is successfully deleted.

Actual Results

It says that the group could not be found and the association remains.

Workaround

1. Re-create the group.
2. Delete the association to the role.
3. Delete the group.

Notes

Although the delete message says that the group information will remain on the instance, the user should be able to delete it afterward.

The error message is bugged on the new UI: