Thanks for this. Seems like this dispatcher override is being used...
On a Local version of the site, after trying a few things (and bombing the site), I eventually restored the Modules folder from an old (recent enough) backup.
An lo and behold, it could save custom values for a feature again 😕 Wtf...
Unfortunately I can't try this shit on Live though as it's technically a different branch and its backups have this bug.
Probably going to be one of those weird unsolved mysteries... Not ideal...
However, does this not assist in giving a clue perhaps: ? I've checked the logs and it appears to be filling up with this error when I try to add a custom product feature value:
[Tue Dec 01 12:47:23.753602 2020] [php7:warn] [pid 18120:tid 1916] [client ::1:52514] PHP Warning: preg_match(): Compilation failed: invalid range in character class at offset 55 in C:\\xamppnew\\htdocs\\development\\testsite\\classes\\Dispatcher.php on line 936, referer: http://localhost/development/testsite/admin3419jgisg/index.php?controller=AdminProducts&id_product=119&updateproduct&conf=4&key_tab=Features&token=ddb9b6bb5c007d48060cae23004fd3ec
This is line 936 in my Dispatcher.php
if (preg_match($route['regexp'], $uri, $m)) {
Either way, I appreciate the assistance @yaniv14