Microsoft 365: Sign in Error 1001

If you are experiencing an issue signing into Microsoft 365 Apps (Word, Office, Excel, or other MS Office suite products) and you are getting an error similar to the one pictured below, here are some steps that can help you log back in


This error can also occur with multiple different numbers but occurs after you enter your username but before you can enter your password.

Close any open Office Applications including Teams

On your computer navigate to c:\users\<yourusername>\appdata\local\microsoft (your username will be the name that is displayed on your screen when you log into the computer). You can paste this into file explorer and it will take you there (after you substitute your username) or you can navigate to it through file explorer

If you do not see the appdata folder it is because it is a hidden folder. For more information on viewing hidden files in windows see this article

Once you are in the microsoft folder, delete the OneAuth and IdentityCache folders. You can also cut and paste them to a different location like your desktop.

Restart the Office application you are trying to access

Click on the Sign-In option

You should now be able to sign-in without issue



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Article ID: 151151
Wed 4/19/23 4:07 PM
Mon 5/20/24 9:59 AM