I would like to add two new menus to my website, but when I create, or even edit a menu and click Save, Save & Close and Save & New nothing happens. With Firebug I get
ReferenceError: Hash is not defined
What should I do?
There's a thread here where people have the same problem, and it suggests just clearing your browser's cache fixes it.
http://forum.joomla.org/viewtopic.php?f=706&t=844728&p=3171823#p3171823
That would make sense if you have recently upgraded it and Joomla have updated a javascript file from the previous version.
If not, might be worth seeing if it works in other browsers, to see if it is a Joomla or a similar browser issue.
Failing that, re-install the latest version to make sure you haven't overridden any core files.