The Special:MobileDiff page is giving me this error after updating to MW 1.35 and the stable 1.35 version of the extension (also tried the master version and had the same issue).
Object of class User could not be converted to int in /var/www/html/w/includes/user/User.php on line 2128
Page example: https://jojowiki.com/Special:MobileDiff/464928
I tried setting $wgMFUseDesktopSpecialHistoryPage to true to see if that would change it to the desktop site's history page instead to hide the error, but it didn't do anything.