Windows Remote Desktop Client fails to connect with error code 0x4

Solution 1:

I reported this issue to MS via their Report Issue form on Mac Remote Desktop client and got the following response:

Set this key to a high value, like 10,000 HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server



Once I followed these recommendations the problem stopped.

Solution 2:

Definitely, a Microsoft issue with RDPv10. Got same issue. Thanks for recommendation shared. Also, reboot of the remote machine helps.