Hello Sean McCully,
Thank you for posting in Q&A forum.
I have found a same error on MAC OS when using Windows Remote Desktop, and you can try the suggestions provided by other users, hope it helps.
RDP Works PC to PC, but I get Error Code 0x204 MAC to PC - Microsoft Q&A
I hope the information above is helpful.
If you have any questions or concerns, please feel free to let us know.
Best Regards,
Daisy Zhou
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