Error code CAA90049 - Any M365 App

Anonymous
2024-04-08T18:25:48+00:00

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]

Microsoft 365 and Office | Subscription, account, billing | For business | Other

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  1. Anonymous
    2024-08-05T14:18:41+00:00

    Got a response back recently from Omnissa (Vmware Horizon) support.

    They stated it is a Microsoft update that broke this function and they themselves are trying to get it resolved with Microsoft.

    They also suggested putting pressure on Microsoft by submitting a ticket with them to fix it in a future update.

    Like others have alluded to in these replies, a temporary fix could be undoing that update. However, I, personally, have not tested this yet to confirm.

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  2. Anonymous
    2024-07-31T12:31:27+00:00

    We had the same problem after an upgrade to Server 2022 with FSLogix HF4 (2.9.8884.27471), after we set the "RoamIdentity" to "1" via GPO it works fine.

    https://learn.microsoft.com/en-Us/fslogix/reference-configuration-settings?tabs=profiles#roamidentity

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  3. Anonymous
    2024-07-30T19:34:23+00:00

    I don't want to speak too soon, but I may have fixed our issue.

    I had been using Golden image without vTPM and having Horizon add the vTPM on the instant clones.

    I created a new pool, used the exact same golden image and snapshot but did not tell Horizon to add the vTPM. I am refreshing on logoff. 2 days now and not 1 user had to disconnect/reconnect the "access work or school" setting. I'm not ready to call it solved after just 2 days, but I'm actually hopeful at this point.

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  4. Anonymous
    2024-07-29T10:17:40+00:00

    Are you using a vTPM chip? We didn't have this issue in Win10, but in Win11 my golden image does not have a vTPM, but as part of the pool creation I add one to the instant clones.

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  5. Anonymous
    2024-07-29T08:31:07+00:00

    We have the same issue. But after a lot of testing we have a temp solution - if we remove KB5040427, it´s working. (I know, it´s not a final solution, but good workaround till Microsoft solve it)
    Our setup: VDI Horizon, Windows 10

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