Dear Louis,
While the “Environment” tab method worked reliably in previous versions, Windows Server 2025 introduces changes to session behavior and application launch permissions that may affect this setup. The group policy you applied—“Start a program on connection”—is effective but applies globally, which limits its flexibility for user-specific configurations. For more granular control, we recommend using RemoteApp publishing via Remote Desktop Services, which allows you to assign specific applications per user or group and automatically close the session when the app exits.
Additionally, the “alternate shell” setting in the RDP file may fail if the executable requires elevated permissions or if the session context lacks access during startup. Verifying that the path is accessible to the user profile and not blocked by AppLocker or other security policies may help resolve this.
If the above response helps answer your question, remember to "Accept Answer" so that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.
Best regards,
Harry Phan