When the Remote Desktop client ( mstsc.exe ) initiates a session, it goes through a multi-step sequence: network discovery, security negotiation, certificate validation, and user authentication. If the process drops before the login prompt appears, Windows throws the 0x904 error. The primary causes include:
Look for the certificate issued to the computer's hostname and check its .
NLA is a security layer that requires the user to authenticate before a session is established. While safer, it often triggers 0x904 if there is a credential mismatch.
Find the hidden file named Default.rdp (you may need to enable "Hidden items" in the View tab) and delete it. Restart the RDP client. Step 5: Registry Tweak for Security Providers When the Remote Desktop client ( mstsc
is a common Windows Remote Desktop Protocol (RDP) fault that occurs when a client machine is abruptly disconnected or denied access while attempting to establish a secure Transport Layer Security (TLS) tunnel with a target server or virtual machine. This error usually triggers immediately upon launching mstsc.exe , preventing users from ever reaching the Windows credentials login screen.
Scroll down the left sidebar menu to the section and click on Run Command .
Extended error 0x7 often points to a session conflict. If the user account has a disconnected session that failed to close properly, the server may reject the new connection. NLA is a security layer that requires the
On the server side, the "ID badge" (the self-signed RDP certificate) might have expired or become corrupted. When your computer asks to see it, the server can't provide a valid one, leading to an immediate 0x904 error. How to Fix It
If the above solutions do not resolve the issue, the following workarounds may help:
Then restart TermService :
Return to services.msc , right-click , and select Start . This dynamically recreates a fresh, uncorrupted RDP certificate structure.
But there was no root-level daemon on that machine. Aris had removed it three years ago.
To resolve errors caused by too many pending connections, run the following in an Admin Command Prompt to increase MaxOutstandingConnections Restart the RDP client
: Upgrades or system migrations can corrupt the MachineKeys folder where Windows securely stores crypto assets, rendering the system unable to read or generate RDP certificates.