After upgrading from OJS 3.1.0.1 to 3.1.1.1 a few weeks ago (and then to 3.1.1.2), file upload processes do not populate the {$userGroup} in the filename with the actual userGroup. The user name and the filename displays correctly.
I have a multilingual installation, but the same happens if I try to upload from the different language environments.
Any guess why this happens and how I can fix it?