For the error PHP NOTICE [8] Trying to access array offset on value of type int in site/pages/modules/groups.php on line 615 (version: 10.0.29, PHP version: 7.4.1

It looks like a fix may be available. Would it be safe to drop the latest groups.php into either modules or modules_custom ?

Same for sources/activities_submission.php where I supressed an error with ..

function log_newest_activity($id, $timeout = 1000, $force = false)
{
    $file_path = get_custom_file_base() . '/data_custom/latest_activity.txt';

    $old_id = @file_get_contents($file_path);    <-----

Would the newer versions in GitLab be okay to drop into place, or would that blow something up

T
 

Yes, both these issues are fixed. Latest files from GitLab should be fine as long as it's from the master branch.
Always overwrite the originals if it is an official fix.