Why is password login for microsoft outlook suddenly unavailable?

Hello,

If clearing the browser cache and cookies was the only change made, one possibility is that your Microsoft account is currently expecting a different sign-in method instead of a password.

Microsoft accounts can be configured for passwordless sign-in, in which case you may see messages such as "Password sign-in isn't available" and be prompted to use Microsoft Authenticator, a security key, SMS verification, or another authentication method instead.

You could clarify :

• Do you still see a password field ?
• What is the exact message displayed ?
• If you select "Sign in another way", which options are offered ?

Based on Microsoft-documented cases, this behavior can be related to a passwordless account configuration, a temporary account restriction, or an identity verification issue.

If you can still access the account through another sign-in method, you can review your security settings here :

https://account.live.com/proofs/manage

Also, if the issue started recently, it may be worth checking the Microsoft service status page :

https://status.cloud.microsoft/

Hope this helps