Clicking Admin Zone -> Tools -> Members results in a bail:

PHP NOTICE [8] Trying to access array offset on value of type null in sources/templates_donext.php on line 331 (version: 10.0.29, PHP version: 7.4.1, URL: /adminzone/index.php?page=admin-cns-members)

Tonight after it slows down a bit I'll step the PHP version back a bit and see if it's related to that.
 

This does like a PHP 7.4 issue. The last patch release was meant to fix everything, but possibly something got missed.

Automated fix message

Chris Graham said

I often see lots of extra spaces being added on Transifex translation. I'm not sure why, perhaps it's due to use of something like Google Translate. Anyway, I've made a patch to make Composr more tolerant of rogue white-space in Comcode and Tempcode…

0004349: Allow looser Comcode and Tempcode syntax - Composr CMS feature tracker

This will be included in the next patch release.

This issue has now been filed on the tracker as issue #4031, with a fix.

Yep, reverting form 7.4 back every minor still Bails, but PHP 5.6 works just fine.

This is spectacular work, Chris. Sometimes when we get deeply involved in a project, and we can't see how big and how amazing a project has become, and how much it helps people. This is really excellent software. Thank you for all the work you do.

Thanks Terry, I really appreciate that ! Actually it means more than you know… right now in my personal life I know a lot of folks who are really struggling badly and I'm not able to help them with their issues, and it's constant disaster on the news this last couple of weeks, and winter viruses are all over - and v11 is such hard work to get out - it's great to know I'm making a positive impact   .

Btw, I just fixed another PHP 7.4 issue which I think is likely also affecting your site (based on automated error emails):
0004033: Error on PHP 7.4 when viewing usergroups - Composr CMS feature tracker