So if your mootools tabs, accordions, animated menus, image sliders or other extensions don't work correctly, don't worry,
there's a fix for that, just follow the steps:
1) Download two files from
2) Change the names of downloaded files by removing '-uncompressed', like this:
3) Upload changed files into
[joomla_root]/media/system/js/ and confirm replacing existing files.
Mootools should work fine now.