module editor corrupt

Hi there, I have installed the Musiccity template and updated the security for joomla etc, the website was working fine then all of a sudden the whole backend for editing modules and menu's is corrupted.

It all looks to be like HTML and php code with no buttons to save changes or any GUI to speak of.

Attached is a Screenshot.

Any suggestions would be good

Do you get this error on same module or all modules.

You can try following.

Reupload files / folders in case you are missing required files.
Disable css / js cache optimizers.
Disable extra security plugins, such as SEF security addons.
Check your servers php memory limit.

See you around...