NLA requires the client to authenticate before establishing a full RDP session. If NLA is enforced on the server but the client fails to negotiate the required security protocols, error 0x904 appears.

Between 2018 and 2020, Microsoft released several patches for to address the CVE-2018-0886 vulnerability. If the client and server have different patch levels (e.g., client fully updated, server unpatched), the connection fails with 0x904 or related errors.

To resolve the Remote Desktop Connection Error Code 0x904 Extended, follow these systematic troubleshooting steps:

Security software or Windows Defender Firewall may be blocking RDP traffic (Port 3389).

To resolve the error, system administrators generally follow a hierarchy of fixes starting with the most likely culprit: Fix Remote Desktop Error Code 0x904: 4 Working Solutions

Adobe Lightroom: what is it, where do you get it, what does it cost in 2026?

Remote Desktop: Connection Error Code 0x904 Extended ((install))

To resolve the Remote Desktop Connection Error Code 0x904 Extended, follow these systematic troubleshooting steps: NLA requires the client to authenticate before establishing

Security software or Windows Defender Firewall may be blocking RDP traffic (Port 3389). If the client and server have different patch levels (e

To resolve the error, system administrators generally follow a hierarchy of fixes starting with the most likely culprit: Fix Remote Desktop Error Code 0x904: 4 Working Solutions