Hi M-DVD, nice to see you back!
I installed v3.1 and got the following error:
Fatal error: Call to undefined function: array_diff_key_() in /home/content/x/x/x/xxxxxxxxx/html/forum/Sources/MessageIndex.php on line 840
Line 840 in my file:
$nousingfilter = empty($user_info['filter_topic']) || !count(array_diff(array_diff_key_($user_info['filter_topic'], array('pages' => '')), array('', '0')));
I noticed that in the first instance you used array_diff but after the bracket you used array_diff_key_
I don't know much php but I had a shot in the dark and removed the '_key_' and tried it. It worked!
The mod seems to function fine so I guess all's good. Let us know if that change affects anything serious or whether it was just a typo on your part.
For those of you playing at home the line should now be:
$nousingfilter = empty($user_info['filter_topic']) || !count(array_diff(array_diff($user_info['filter_topic'], array('pages' => '')), array('', '0')));