I've got an iMac 2013 running the latest version of Sierra. Recently clean installed. The issue is that every time I open an Excel document in Numbers, it crashes immediately. Even a blank document. I also have another identical Mac also on the latest version of Sierra -- issue doesn't happen at all. Numbers on iPhone works fine too. Can even export it as a Numbers document and send it to the Mac and it works. Tried uninstalling, removing all pref files, re-installing... works the first time but then every time after that it causes it to crash. It also crashes when exporting a Numbers document in the Excel format. These problems all happen with Pages & Word too. Any idea how I can troubleshoot this...?