Error 0x11 corresponds to ERROR_NETWORK_UNREACHABLE. The RDP client successfully resolved the remote hostname (unlike 0x3) but could not establish a TCP connection to port 3389. The network route is blocked or missing.
Note: This is a temporary fix for testing or lab environments. You should install proper RDS CALs for production.
If the 120-day grace period is corrupt or reporting false errors, you can reset the Grace Period timer.
If you are analyzing RDP logs or network traces and encounter the signature "rdp 0x3 0x11", you are dealing with a specific server-side disconnection event. This hex code combination indicates that the Remote Desktop Session Host (RDSH) terminated the connection due to a failure in the licensing handshake.
This post breaks down what these codes mean and how to resolve the underlying issue.
Can you connect to port 3389?
(Test-NetConnection remotePC -Port 3389)
Microsoft patches often tighten CredSSP. An older client trying to connect to a fully patched server (or vice versa) can result in 0x3 0x11 due to protocol version mismatches.
The RDP error codes 0x3 and 0x11 are intimidating at first glance, but they are highly solvable. In 80% of cases, the problem stems from a corrupt RDP certificate or a transient client cache issue. By methodically resetting the certificate, verifying NLA settings, and checking your network path, you can restore remote connectivity within minutes.
Remember: Document each fix you apply. The next time rdp 0x3 0x11 appears in your logs, you will be ready.
Keywords used: rdp 0x3 0x11, Remote Desktop Protocol error, fix RDP 0x3 0x11, RDP certificate regeneration, Network Level Authentication error, CredSSP patch.
The error RDP 0x3 0x11 (Error Code 0x3, Extended Error Code 0x11) typically occurs on Windows Server 2022 and Windows 11. It indicates a protocol transport failure, often caused by UDP instability or conflicts with the Microsoft Remote Display Adapter.
Below is a technical white paper summarizing the causes and documented resolutions for this issue. Technical Analysis: RDP Error 0x3 (Extended 0x11) 1. Error Definition rdp 0x3 0x11
Status Code 0x3: ERROR_PATH_NOT_FOUND or general connection establishment failure.
Extended Code 0x11: Often mapped to ERROR_NOT_SAME_DEVICE or a protocol-level mismatch where the client fails to render the session after authentication. 2. Primary Root Causes
UDP Transport Issues: A common cause is the Remote Desktop client's inability to maintain the UDP heartbeat through firewalls or NAT. Disconnections often occur exactly 30 minutes into a session.
Virtual Display Driver Conflicts: The "Microsoft Remote Display Adapter" can become corrupted or conflict with physical hardware drivers, causing the screen to remain black before disconnecting.
Monitor Detection Logic: Turning off a physical monitor on the host can trigger this error if Windows interprets it as a "removed display," instantly killing the RDP session. 3. Documented Resolutions Method A: Force TCP Protocol (Registry Fix)
Disabling UDP forces RDP to use the more stable TCP transport, bypassing many timeout issues.
The error code 0x3 (Extended Code 0x11) in Remote Desktop (RDP) indicates an immediate disconnection usually caused by a protocol or licensing conflict following a Windows update. Microsoft Learn Primary Fix: Address KB5055528
This specific error is frequently linked to the cumulative update
(released April 11, 2025). The most effective solution is to remove this update and block it from reinstalling. Uninstall via Command Line Command Prompt PowerShell as an Administrator. Run the following command: wusa /uninstall /kb:5055528 Restart your computer after the process completes. Uninstall via GUI Windows Update Update history Uninstall updates in the list and click Alternative Troubleshooting
If removing the update does not resolve the issue, try these steps: Reset RDP Services services.msc Remote Desktop Services , and select Disable Network Level Authentication (NLA) : On the host machine, go to System Properties
and uncheck "Allow connections only from computers running Remote Desktop with Network Level Authentication". Clear RDP Cache : Delete the Default.rdp file in your Error 0x11 corresponds to ERROR_NETWORK_UNREACHABLE
folder (it is hidden by default) and clear the RDP bitmap cache in the Remote Desktop Connection app settings. Check Firewall : Ensure that
is open and that Remote Desktop is allowed through the Windows Defender Firewall. SupportPRO PowerShell script to automate the removal and blocking of this update?
The error code in the context of Remote Desktop Protocol (RDP) typically refers to a Protocol Error detected at the client side, often specifically linked to a License Protocol Error
or a failure in the handshake between the client and the terminal server.
Below is a deep-dive post covering the technical breakdown, root causes, and advanced resolution steps.
Understanding RDP Error 0x3 0x11: The Protocol Handshake Failure When you see a message like
"Because of a protocol error detected at the client (code 0x3), this session will be disconnected," you are witnessing a breakdown in the OSI Layer 7 (Application) communication between the RDP client and the host. The sub-code
(often paired with 0x3) specifically points toward an issue in the Licensing Phase of the RDP stack. 1. The Core Root Causes Stale Licensing Registry Keys:
The most common culprit. The client machine stores local "MSLicensing" certificates that can become corrupt or lose synchronization with the server. Security Layer Mismatch: A conflict between Network Level Authentication (NLA) and the RDP Security Layer (Standard RDP vs. TLS). Bitmap Cache Corruption:
Temporary display data stored on the client can sometimes trigger protocol inconsistencies during the initial screen draw. MTU/Packet Fragmentation:
If the network path has a low Maximum Transmission Unit (MTU), the larger licensing packets may drop, causing the protocol to fail at the "0x11" stage. Step-by-Step Resolution Guide Phase 1: Clear the Client-Side Licensing Store Can you connect to port 3389
Since 0x11 is frequently a licensing handshake failure, resetting the client's local store is the first step. Close all RDP windows. Registry Editor (regedit) as an Administrator. Navigate to: HKEY_LOCAL_MACHINE\Software\Microsoft\MSLicensing Right-click the MSLicensing folder and select
. (Windows will regenerate this upon your next successful connection). You must run the Remote Desktop Connection app as Administrator
the first time after doing this to allow it to recreate the registry keys. Phase 2: Adjust Security & NLA Settings
If the registry fix fails, the server and client may be disagreeing on the encryption level. Disable NLA temporarily: On the target machine, go to System Properties > Remote
and uncheck "Allow connections only from computers running Remote Desktop with Network Level Authentication". Force RDP Security Layer: Group Policy Editor on the server: Navigate to:
Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Security
Set "Require use of specific security layer for remote (RDP) connections" to Phase 3: Network & Display Optimization Disable Persistent Bitmap Caching: In the RDP Client (mstsc.exe), go to the Experience
tab and uncheck "Persistent bitmap caching." This prevents the client from loading potentially corrupt cached UI elements. Update Display Drivers:
On the host machine, ensure drivers are current, as RDP relies on the WDDM (Windows Display Driver Model) to virtualize the desktop session. Summary Table: RDP Error 0x3 0x11 Error Type Protocol Handshake / Licensing Failure Layer 7 (Application) Primary Fix MSLicensing Registry Key Common Trigger Corrupt client-side certificates or NLA mismatches registry cleanup using a PowerShell script for multiple workstations?
Explain Like I'm 5: Remote Desktop Protocol (RDP) - CyberArk
You will typically see a generic dialog box: "An internal error has occurred."
But behind the scenes, the Event Viewer tells the real story:
Built to revive your Mac — empowering old devices with new life.