Windows
Microsoft apps showed an error after a conditional access change
Microsoft apps were throwing an error because a recent conditional access policy change blocked legacy authentication. The policy change was reverted and the user confirmed the issue was resolved.
Killed once by someone from XL.net, on 2025-10-16.
Affects
Versions
- Windows 11 24H2
Apps
- Microsoft apps
What you see
- Microsoft apps return an error when the user tries to sign in or use them.
Why it happens
Likely A conditional access policy change blocked legacy authentication and caused the same error for affected users.
When it shows up
Multiple users suddenly see the same Microsoft apps error after a conditional access policy update.
You are in this case if:
- Conditional access policy recently changed to block legacy authentication
- Same error reported by multiple users
1 fix below
The steps that killed it
The steps are behind a quick check
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Keeping it away
- Review conditional access changes before re-implementing legacy authentication blocks.
Someone from XL.net killed this on a Windows computer on 2025-10-16. It is written up from that one repair, so it cites no outside page.