Hello, I have a remote end user that is receiving this error code when trying to sign into any M365 app. Once we close the error message the apps work perfectly fine but this happens daily when signing on and I would like to find a permanent fix. I would attach a screenshot but that doesn't seem to be working right now. User enters login credentials and Microsoft authenticator code then this error pops up for any m365 app / teams / OneDrive. User is in another state so can't come into office. Something went wrong We couldn't sign you in. If this error persists, contact your system administrators and provide the error code CAA90049. Error code: CAA90049 Correlation ID: 9a55***1d07 Server message: Session key is empty Any help is appreciated. Thank you [PII is removed by moderator]

Something that worked on our end (as IT) was force signing out the user out of all instances of Microsoft and having the user reboot their device. We did confirm it was only affecting the Teams application, not anything else in the Microsoft ecosystem. Before attempting this, I verified that our user had access to Teams through the web application. Hopefully this helps someone.

Hi, Please assist with below, error code shows CAA90049

Hi, In my case, it would only be enough for the user in the A365 administrator to delete the Microsoft 365 activations and close all active Microsoft 365 connections. Thanks,

Guys! Please remove your work account from settings, disconnect the device from the organization, and then re-add it and sign in again. That fixed my issue.

Error code CAA90049 - Any M365 App

Anonymous

Hello, I have a remote end user that is receiving this error code when trying to sign into any M365 app. Once we close the error message the apps work perfectly fine but this happens daily when signing on and I would like to find a permanent fix. I would attach a screenshot but that doesn't seem to be working right now.

User enters login credentials and Microsoft authenticator code then this error pops up for any m365 app / teams / OneDrive.
User is in another state so can't come into office.

Something went wrong

We couldn't sign you in. If this error persists, contact your system administrators and provide the error code CAA90049.

Error code: CAA90049

Correlation ID: 9a55***1d07

Server message: Session key is empty

Any help is appreciated.

Thank you

[PII is removed by moderator]

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

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Anonymous

2025-04-03T15:39:59+00:00

Something that worked on our end (as IT) was force signing out the user out of all instances of Microsoft and having the user reboot their device.

We did confirm it was only affecting the Teams application, not anything else in the Microsoft ecosystem. Before attempting this, I verified that our user had access to Teams through the web application.

Hopefully this helps someone.
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Anonymous

2025-02-12T16:29:12+00:00

worked for me as well
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Anonymous

2025-01-29T08:45:57+00:00

Hi,

Please assist with below, error code shows CAA90049
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Anonymous

2025-01-24T18:09:08+00:00

Hi,

In my case, it would only be enough for the user in the A365 administrator to delete the Microsoft 365 activations and close all active Microsoft 365 connections.

Thanks,
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Anonymous

2024-09-22T23:56:17+00:00

Guys!

Please remove your work account from settings, disconnect the device from the organization, and then re-add it and sign in again. That fixed my issue.
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