Q. Cant add page numbers, headers or footers to a word 2007 document Error-:" The Office Open XML file BuildingBlocks.dotx cannot be opened because there are problems with contents ". A: 1. Close any office program that may left open. 2. Open the folder " C:\Documents and Settings\%username%\Application Data\Microsoft\Document Building Blocks\1033 " 3. Delete the " BuildingBlocks.dotx " file. 4. Open Word and close it. 5. Wait a few seconds. 6. Open a new blank page, and try to add page numbers, headers or footers. 7. Optional: Open the folder " C:\Documents and Settings\%username%\Application Data\Microsoft\Document Building Blocks\1033 " Verity that a new " BuildingBlocks.dotx " file, was created. Thanks Techhsuff Team.