Hi Cemee,

indeed that looks weird. I will check and let you know.

It looks that something is locking Joomla and extensions javascript files... It's how your Joomla admin login screen look like on my Firefox / Windows:

So yes it may hurt menu items features as well. Maybe it's caused by your .htaccess file or used firewall, please check it deeply. For sure it's not normal Joomla behavior, so it was made by your actions/mistakes or hacker. Reinstall Joomla core and check used extra plugins etc.