Describes the cause and action for error messages.
Error Message(English)：
unable to sign into excel 2016
Excel help - Office Support
https://support.office.com/en-us/excel
Office Asks for Login Password When Save Files to OneDrive / Office ...
https://techjourney.net/office-asks-for-login-password-when-save-files-to-onedrive-office-365-upload・・・
MS office Can't Open or Repair Problem Fix - word or Excel Document ...
https://www.youtube.com/watch?v=jpNXsROJz4s
https://www.youtube.com/watch?v=jpNXsROJz4s
Microsoft Excel: the file is corrupted and cannot be opened - 2016, 2013
https://www.youtube.com/watch?v=jOsSqww70S8
https://www.youtube.com/watch?v=jOsSqww70S8
How to Uninstall and Completely Remove an Excel Add in - YouTube
https://www.youtube.com/watch?v=5MVbR4pKAbU
https://www.youtube.com/watch?v=5MVbR4pKAbU
How to Install an Excel Add in - YouTube
https://www.youtube.com/watch?v=reuU2zUsEPM