Microsoft shared a workaround for a known Microsoft 365 issue triggering 'Something Went Wrong [1001]' sign-in errors and making desktop applications unusable for many customers. 

The login issues affect those using Excel, Word, Outlook, and PowerPoint for Microsoft 365, Microsoft 365 Apps for business, and Office apps for iOS and Android.

"When users attempt to sign into Microsoft 365 desktop applications, they receive an error message," the company says.

"We are experiencing a problem with SSO with Office 365 apps (outlook, onedrive). After signing in to the AVD, the office apps are not signed in, they remain stuck," one affected user said.

"It is an Azure AD joined windows 11 AVD host. The authentication pop-up say something when wrong [1001]."

While these errors may be encountered when trying to sign in to Microsoft 365 desktop applications on systems when security software blocks Web Account Manager (WAM) plug-ins from running, Redmond is also investigating these login problems as a separate issue by reviewing logs from impacted users.

Microsoft also asked affected customers to open support tickets in the M365 Admin Portal and attach Microsoft Office Authentication/Identity Diagnostic (MSOAID) logs to speed up the investigation. 

Microsoft advises users experiencing issues opening Microsoft 365 apps to use the Outlook Web App (OWA) and Office web applications or mobile applications as a workaround.

Redmond says that the following steps might also help to get rid of the sign-in errors:

• Rebooting the device often helps to mitigate the issue.
• Run the commandlets below in user mode PowerShell to repair WAM (more context in the Fix authentication issues in Office applications when you try to connect to a Microsoft 365 service article):

Additional guidance is available on Microsoft's support website on how to fix Office app authentication issues when connecting to a Microsoft 365 service and on what to do when you can't sign in to Microsoft 365 desktop apps.