Hi @Adrian Leo,
Welcome to the Microsoft Q&A Platform! Thank you for asking your question here.
Azure Virtual Desktop users might encounter sign-in issues that result in a black screen. There are multiple possible causes for black screens, but users can be impacted from issues synchronizing with AppReadiness, and multiple sessions signing in or out.
Please refer to this-https://learn.microsoft.com/en-us/previous-versions/troubleshoot/windows-server/windows-virtual-desktop-blank-screen
Here are a few similar issues that occurred earlier, which might help you resolve the problem.
https://learn.microsoft.com/en-us/answers/questions/2099593/avd-black-screen-on-windows-launch
If you have any further queries, do let us know.
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