It's amazing how Office manages to be incompatible with anaything else. Word and Excel files have grown up into bloated monsters full of unheard-of features that always make programs like open office and mobile versions of the programs break when they read less simple files. I can never fill simple forms that are sent to me because they are never opened quite right in openoffice. And it is quite annoying that it can't diagnose exactly where can be a problem when you switch file formats.