Excel 2007 unable to save as xlsx

Describes the cause and action for error messages.

Error Message(English)：
2007 unable to save as xlsx

Resolution

How to troubleshoot errors when you save Excel workbooks
https://support.microsoft.com/en-hk/help/271513/how-to-troubleshoot-errors-when-you-save-excel-workb・・・

How to Fix Excel File Error 'The document cannot be saved'
https://recoverit.wondershare.com/office-file-recovery/how-to-fix-excel-document-cannot-be-saved-err・・・

Save a workbook in another file format - Excel - Office Support
https://support.office.com/en-us/article/save-a-workbook-in-another-file-format-6a16c862-4a36-48f9-a・・・

Save an Excel workbook for compatibility with earlier versions of Excel ...
https://support.office.com/en-ie/article/save-an-excel-workbook-for-compatibility-with-earlier-versi・・・

could not be saved sharing violation EXCEL SOLVED - YouTube
https://www.youtube.com/watch?v=P9lRCKCJP14

https://www.youtube.com/watch?v=P9lRCKCJP14

Microsoft Excel: the file is corrupted and cannot be opened - 2016 ...
https://www.youtube.com/watch?v=jOsSqww70S8

https://www.youtube.com/watch?v=jOsSqww70S8

Cannot get out of compatibility mode in Excel 2007 - Super User
https://superuser.com/questions/83199/cannot-get-out-of-compatibility-mode-in-excel-2007