User can't sign in to device - error 50155

Question

It's possible to log in to the device with another account, but receive the "Device authentication failed" when using a different user. Does the user licence have an impact? The first user has full MS365 licence. Second user, just exchange online.

Answer 1

Hello @Dan Goodson ,

Thanks for reaching out.

No, "Device authentication failed" (error 50155) could happen for several reasons like device is disabled or pending on AAD.

You could verify device status from Azure portal --> Azure AD --> Devices --> All devices

Disabling : Disabling a device prevents it from authenticating via Azure AD
Pending : Pending devices indicates that the device has been synchronized successfully using Azure AD connect form
your on-premise Active Directory and it is ready for device registration, but is not registered to Azure AD yet.

If it is Azure AD join kindly remove the device from Azure AD and try joining back then check whether you were receiving error message again. To fix the problem, unregister the device by running dsregcmd /debug /leave and dsregcmd /debug /join at an elevated command prompt.

or if it is an Hybrid Azure AD join then Verify that the device is synced from cloud to on-premises or is not disabled. Sync cycles may be delayed since it syncs the Key after the object is synced.

Reference: https://learn.microsoft.com/en-us/azure/active-directory/devices/device-management-azure-portal#enable-or-disable-an-azure-ad-device

Hope this helps.

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