"Cannot edit range" in X7 and X8

This hasn’t worked for me unfortunately. I removed Mendeley as a programme and add-in in Word but I have the same issue with EndNote. 

I mainly use the online version of EndNote but this problem appears with the desktop version as well. Also, I don’t always get a ‘cannot edit range’ error - if I try to add a new reference to a document with existing Endnote reference, it adds them as text within the document, rather than following the selected referencing style. 

Any other suggestions? I’ve also tried ‘repairing’ Word but that didn’t seem to work either.

Thanks.