I backed up my QB file and the "Attach" folder.  I then restored my backup to a new unique folder and moved the "Attach" folder into the same folder where my restored QB file is located.  If I go to the Doc Center, all my supporting documents are there (over 3000).  When I go to an individual invoice, however, the attachment paper clip is not shown.  I went to my QB program, selected Company->Documents->Repair Attached Document Links.  When I clicked on "Repair Links" I got the following message "This doesn't look like the right Attach folder for your company file".  I looked inside the Attach folder and the sub-folder with the documents was labelled "TXN".  I changed the name to match my company file, but the result is the same.  I recognize I can search the document center to find my supporting files, but apparently I need more help to re-attach or repair the links?