Vendor records not loading

Vendor records not loading

Only on some vendors, notes, products, activities and attachments do not load on the page view.  We receive a perpetual message that the page is "loading".  Directly under where you can select hide details, it also says "undefined".  No idea what that means.  This does not happen on all vendors, but it happens on certain ones consistently.  Please see attached screen shot.  Does anyone know what could be causing this error?