Hello @Onat Atayer ,
Thank you for posting your query on Microsoft Q&A. Based on the error code 53003, it seems the sign-in is failing due to a Conditional Access policy, and the device being used is unregistered.
To help resolve this issue, please check the Entra sign-in logs in the Azure portal to identify the affected Conditional Access policy.
Please follow these steps to understand which Conditional Access policy is causing the issue:
- Sign in to the Azure Portal.
- Go to Microsoft Entra ID > Sign-in logs.
- Find the specific sign-in event related to the issue by filtering with the correlation ID.
- Once you've located the sign-in event, select the Conditional Access tab. This will show the policy that caused the sign-in failure.
- Understand why the policy is getting failed or what is not getting satisfied from the CA policy
- If you are not sure what is failing from CA policy, please attach a screenshot of it. So that I can provide your further details.
I hope this information is helpful. Please feel free to reach out if you have any further questions.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Thanks,
Chaithra.