Fatal Error on line 93 of upfront/library/class_upfront_compat.php
$screen = get_current_screen();
Commenting it out fixes the problem, apparently, and it works briefly if left uncommented afterwards. Unfortunately, it yields this error again after some time and it is resolved again by commenting out the above line.
I admit I do not know the implications of this error nor if I can leave it commented without other consequences. This bug began after setting up a series of changes in Defender, mainly enabling auditing and regular scans.
The site displays normally, but the dashboard is inaccessible when line 93 is uncommented.
I appreciate your insight into this matter!