This is a PHP8 error, but it's probably a good idea to fix anyway. https://github.com/open-lms-open-source/moodle-mod_hsuforum/blob/3563bb7c07000e8b40fc8d333edc9f32fb8917b4/lib.php#L2159-L2160 $totalcount is a required param but follows optional params - which doesn't make much sense.