$ is not a function

I am currently unable to use any of the Ajax functionality in the backend of Hika Shop Essential as a result of this error (shows in the Error Console in Firefox). As a result I am unable to add an associated product listing module etc... I have seen that this may be a mootools issue but I am using the default admin templates with minimal components/modules installed and don't see where this conflict is coming from. Can someone steer me in the right direction as this is extremely frustrating.

I finally solved the issue, It was a jQuery issue with jquery++ - I disabled that and now it works.