0x904 Source: Microsoft Remote Desktop (RDP) Client Affected Platforms: Windows (All versions), macOS, iOS, Android
| Error Code | Likely Cause | Typical Fix | | :--- | :--- | :--- | | | CredSSP downgrade detected – encryption level mismatch | Update both sides or adjust encryption oracle policy | | 0x907 | CredSSP encryption error – but the client is blocked explicitly | Client registry override ( AllowEncryptionOracle ) | | 0x516 | Account is locked, disabled, or expired | Check Active Directory / Local User properties | | 0x12f | SSL certificate mismatch / self-signed cert rejection | Import cert or disable cert validation | i--- Remote Desktop Connection Error Code 0x904
Often, the issue is local to your machine rather than the server. 0x904 Source: Microsoft Remote Desktop (RDP) Client Affected
Go to and ensure both Remote Desktop and Remote Desktop (WebSocket) are checked for Private and Public networks. Fix Azure VM Corruption : i--- Remote Desktop Connection Error Code 0x904
If using a hostname fails, try connecting directly to the server's IP address (e.g., 192.168.1.100 ) to bypass DNS or resolution bugs. :