Thanks for the response Ken.
purge-caches.php still doesn't resolve the issue or even deleting the files/folders on the cache. The solution is disabling the slash arguments (Site administration --> Server --> HTTP --> uncheck, 'Use slash arguments' --> Save Changes) and per reference to the forum answer. Or adding this line in the config.php
purge-caches.php still doesn't resolve the issue or even deleting the files/folders on the cache. The solution is disabling the slash arguments (Site administration --> Server --> HTTP --> uncheck, 'Use slash arguments' --> Save Changes) and per reference to the forum answer. Or adding this line in the config.php
$CFG->slasharguments = false;
However even disabling the slash arguments, the icons are not fully regenerated or loaded. I used to run to fix it by rebuilding the CSS themes via ssh.
php admin/cli/build_theme_css.php