Messed up backend - Common
– Messed up backend.
– Slide editor doesn’t work.
– Live preview doesn’t show the slider.
In Joomla there aren’t many extensions loading their codes in the backend of other extensions, probably you have one specially for the admin area. Go to the Extension Manager, and unpublish it to see if it solves the problem. If not, then you could check it out with Firebug or turn on the error reporting like this to see the php errors.