Error while accessing a RDP app through azure app proxy

Hi @Ravi Wanasinghe,

Thank you for reaching out on the Microsoft Q&A forum.

I understand that you are unable to access your RDP application through Azure AD Application Proxy.

To help investigate further, could you please confirm the following:

1. Are you using Azure Firewall or a third-party firewall (and if third-party, what vendor)?
2. Does the firewall require user authentication or login before RDP sessions?
3. Is Network Level Authentication (NLA) enabled on the target RDP host?
4. Have RBAC roles like Virtual Machine User Login or Virtual Machine Administrator Login been assigned to the user, and at what scope?
5. Are you connecting from a corporate network, VPN, or public internet?

Kindly confirm the above details to help narrow down the cause.

Thanks,

Thanmayi