Hi @acecross33 ,
What kind of file format are you trying to open in Office for Mac 2013?
Did this problem appear in all files or a specific file?
I suggest you check if the file is protected and you can try to send the file to Office for Windows desktop app. Then open it and re-save it as a new kind of file format.
Try to provide more information about this problem and I'm glad to help you.
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