For people using TaskChain, I have also fixed the "Select All/None" functionality on TaskChain for Moodle >= 3.3.
The latest version of TaskChain, release 2017-10-04 (52), also fixes an issue that appeared in release 2017-08-29 (50), whereby it was not possible to edit TaskChain settings or create a new TaskChain, My apologies to anyone affected by that bug, and my thanks to user "UVa Uva" for bringing it to my attention.
Best regards
Gordon