Can't log in to laptop with 50155 error

Question

Can't log in to laptop with 50155 error

Karl Raphael 25

We have a user who can no longer log on to her laptop using her company log in. The error is the admin centre logs is 50155, Device authentication failed.

The device does not show up on the list of devices in Entra, and the only way I can find to add the laptop is from the device itself, which we are unable to log into.

Surya Prakash Kotte 2,870 Reputation points Microsoft External Staff Moderator

2025-05-27T06:33:20.73+00:00

Hello @Karl Raphael

Thanks for reaching out.

"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 you're on-premises 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 a 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

I hope this information is helpful. If not, please let us know — we’re happy to assist you.
Eric Nguyen 1,025 Reputation points Independent Advisor

2025-05-27T07:14:12.2733333+00:00

Hi @Karl Raphael,
Here are some more information that I got:
Device Deleted from Azure Portal or Removed from AAD Connect Sync OU

Error 50155 can also be triggered if the device was deleted from Microsoft Entra ID or removed from the AAD Connect Sync Organizational Unit (OU). To resolve this:

Verify AAD Connect Sync OU and perform a manual sync:

Open Synchronization Service App, select your domain, and run a full synchronization.

OR execute the following PowerShell command with elevated permissions:

Start-ADSyncSyncCycle -PolicyType Full
Karl Raphael 25 Reputation points

2025-05-27T19:29:02.0833333+00:00

Hi Surya,

As mentioned the device doesn't show in the device list. If I click on the device id from the sign in logs it says this:

"Device with ID a3fb7067-25e8-4c79-903a-6448f5b3d27b was not found in Microsoft Entra"
Surya Prakash Kotte 2,870 Reputation points Microsoft External Staff Moderator

2025-05-28T09:46:47.36+00:00

Hello @Karl Raphael ,

I would like to check this up offline with you to understand the scenario better. Please share your contact details over private message and your availability for a call.

Accepted answer

0 additional answers

Your answer

Surya Prakash Kotte 2,870 Reputation points Microsoft External Staff Moderator

2025-05-27T06:33:20.73+00:00

Hello @Karl Raphael

Thanks for reaching out.

"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 you're on-premises 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 a 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

I hope this information is helpful. If not, please let us know — we’re happy to assist you.
Eric Nguyen 1,025 Reputation points Independent Advisor

2025-05-27T07:14:12.2733333+00:00

Hi @Karl Raphael,
Here are some more information that I got:
Device Deleted from Azure Portal or Removed from AAD Connect Sync OU

Error 50155 can also be triggered if the device was deleted from Microsoft Entra ID or removed from the AAD Connect Sync Organizational Unit (OU). To resolve this:

Verify AAD Connect Sync OU and perform a manual sync:

Open Synchronization Service App, select your domain, and run a full synchronization.

OR execute the following PowerShell command with elevated permissions:

Start-ADSyncSyncCycle -PolicyType Full
Karl Raphael 25 Reputation points

2025-05-27T19:29:02.0833333+00:00

Hi Surya,

As mentioned the device doesn't show in the device list. If I click on the device id from the sign in logs it says this:

"Device with ID a3fb7067-25e8-4c79-903a-6448f5b3d27b was not found in Microsoft Entra"
Surya Prakash Kotte 2,870 Reputation points Microsoft External Staff Moderator

2025-05-28T09:46:47.36+00:00

Hello @Karl Raphael ,

I would like to check this up offline with you to understand the scenario better. Please share your contact details over private message and your availability for a call.

Answer 1

Surya Prakash Kotte 2,870 Microsoft External Staff Moderator

Hello @Karl Raphael

As we discussed on the call, the device you're trying to log into is already registered with a different domain. To proceed, you'll need to wipe the device and reset it to factory settings. Once it's been reset, you can set it up as a new device and join it to your domain.

If all your concerns have been resolved, I’d greatly appreciate it if you could mark this answer as Accepted. This helps both our team and others in the community.

Share via

Can't log in to laptop with 50155 error

0 additional answers

Your answer