Fatal error

I recently began getting this error when attempting to access the network admin site(s):

Fatal error: Call to a member function printJavascript() on a non-object in D:\Hosting\11019563\html\dev\wp-content\plugins\hover\inc\admin.php on line 276

Here is the code from line 276: $xajax->printJavascript(HOVER_BASE.’/xajax’);

Not sure why it started or how to correct it. Please provide any direction or help you can.

Thanks in advance!