Save changes button not working

The header works fine on the site but the save changes button in the admin panel does nothing. I noticed this first after I checked “enable search bar” and the search bar did not appear. After that, the save changes button stopped working. I tried disabling-enabling and uninstalling-reinstalling and the awesome sticky header plugin but the same problem was there.

I am using the Hub theme from WooThemes and a bunch of plugins.

Any ideas what this might be caused by?

https://www.ads-software.com/plugins/awesome-sticky-header/