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]

I have a user with the same issue after he updated and rebooted. Apps repeatedly ask for a sign in, even using the web apps. We also get a 1001 error when signing into Office desktop apps. I have updated Office, cleared credentials, removed / added registry keys, removed folders from their AppData, etc. None of the fixes online are working. Couple of things. The client I'm having issues with is federated and using single sign on. And I found that I could log into a different Office 365 account in Office and it will accept the sign in. Could be something on the back end with Entra.

Does anyone have a firm solution here? I have VDI users getting this error.

Has anybody found a fix for this issue? We've been running with this issue for months using VMWare Horizon VDI

Actually i might have found a solution. sign out from every Microsoft app and close them delete your own certificates in the internet properties (content -> certificates) delete every office/teams or microsoft related credentials in the "windows credentials" in the credential manager in the control panel if you had any smartcard related certificates reseat your connected smartcard so the certificates can load again. Sign into any microsoft app

This issue can occur on first login. So the first time a user signs into Windows/Office, a user gets this error. Nothing to "clear" then as the profile is brand new. Seen this issue in Windows 10 too. Not just VDI for us.

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.

0 comments

67 answers

Anonymous

2024-06-13T15:24:29+00:00

I have a user with the same issue after he updated and rebooted. Apps repeatedly ask for a sign in, even using the web apps. We also get a 1001 error when signing into Office desktop apps. I have updated Office, cleared credentials, removed / added registry keys, removed folders from their AppData, etc. None of the fixes online are working.

Couple of things. The client I'm having issues with is federated and using single sign on. And I found that I could log into a different Office 365 account in Office and it will accept the sign in. Could be something on the back end with Entra.
Was this answer helpful?

1 person found this answer helpful.

0 comments No comments
Anonymous

2024-06-21T01:17:14+00:00

Does anyone have a firm solution here? I have VDI users getting this error.
Was this answer helpful?

0 comments No comments
Anonymous

2024-06-26T03:59:05+00:00

Has anybody found a fix for this issue? We've been running with this issue for months using VMWare Horizon VDI
Was this answer helpful?

1 person found this answer helpful.

0 comments No comments
Anonymous

2024-06-26T08:23:22+00:00

Actually i might have found a solution.

sign out from every Microsoft app and close them

delete your own certificates in the internet properties (content -> certificates)

delete every office/teams or microsoft related credentials in the "windows credentials" in the credential manager in the control panel

if you had any smartcard related certificates reseat your connected smartcard so the certificates can load again.

Sign into any microsoft app
Was this answer helpful?

0 comments No comments
Anonymous

2024-06-26T11:19:14+00:00

This issue can occur on first login. So the first time a user signs into Windows/Office, a user gets this error. Nothing to "clear" then as the profile is brand new. Seen this issue in Windows 10 too. Not just VDI for us.
Was this answer helpful?

0 comments No comments