Use the "Insert Citation" button to add citations to this document.

Hey, I've written a number of referenced documents using Mendeley and added biblio's to the end. I then deleted them in order to add all of them to a master doc. Now I want to add bibliographies in the separate files and all Mendeley is saying is: Use the "Insert Citation" button to add citations to this document. If I add new references it does work, but it utterly ignores old ones... People have posted about the issue before, and all you ever ask is 'send me the problematic document'. This is all fine, but please post what the issue was after so the rest of us can try to solve the issue on our own as well...