Remote Desktop Connection Error Code 0x904 Extended Error Code 0x7 Best [upd] Access

authentication level:i=0 enablecredsspsupport:i:0

Let me know if this solves your 0x904 / 0x7 issue — or if you need help finding which fix applies to your specific setup.

If all else fails, the remote machine’s RDP listener is corrupted. This is the fix for deep-seated issues.