Hi - I have a corrupted Excel file which I can't repair. Cannot attach the file writes that "The file type you are attempting to upload is not allowed." When I open the file writes that "cannot open the file because the file format or the file extension is invalid. Make sure the file is not corrupted and the file name extension matches the format".It's Excel 2010 . Thanks.
That file is beyond repair. I changed the extension to .XLS and forced it to open up and there is just gibberish inside of it. Do you have a backup or older version you can go back to? may be it will help to restore at least some of the information. See if the following article would help: http://community.office365.com/en-us/f/172/t/256362.aspx