Well, my initial thought is to have whomever sent you the TOC by itself to have them send the TOC as a .pdf file. Otherwise, if it is a protected document/file and it takes you to the edit mode, you will always get the error notification because it would be looking for the TOC headings...and, if you do not have the body text you cannot get the headings and the subsequent page numbers. (I may not have explained it correctly but, the end result would be the same).