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Excel cannot open the file ___.xlsx' because the file format or file extension is not valid. MacOS

Anonymous
2024-07-18T12:18:59+00:00

When opening any Excel files all are unable to open and have an error.

Microsoft 365 and Office | Excel | For business | MacOS

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  1. Jim G 133.9K Reputation points MVP Volunteer Moderator
    2024-07-18T15:04:00+00:00

    One common cause of this is having special characters in the file name, an enclosing folder, or the startup volume name. Check to be sure all characters are either letters or numbers.

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  2. Anonymous
    2024-07-18T15:18:15+00:00

    Hi Jim,

    Thanks for the response.

    But all the excel files i have are opening before and no issues with the file naming.

    Upon testing i can open the excel files on Excel via Web (Online). But when i tried to open the files using Excel App error will prompt.

    MS Apps are also up to date. Tried to re-install MS Apps too.

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  3. Jim G 133.9K Reputation points MVP Volunteer Moderator
    2024-07-19T17:45:14+00:00

    Since the file will open on-line, do that, make a small change to the workbook, then save the changed version to your Mac. That might remove corruption that could be causing the error.

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