Fix RPC_X_SS_IN_NULL_CONTEXT (0x000006EF) in 3 Steps

What's This Error About?

I know seeing 0x000006EF on a server or PC is frustrating. It usually pops up when a program like SQL Server, Exchange, or even Outlook tries to talk to another machine over RPC but sends an empty (null) context handle. The server looks at that and says "nope, can't work with nothing."

This happened to me a few years ago on a Windows Server 2019 running SQL Server 2017. A client app kept crashing with this exact code. The fix ended up being super simple, but only after I wasted an hour chasing the wrong thing. Let me save you that hour.

Step 1 – The 30-Second Fix: Reboot Both Machines

Before you touch any settings, reboot the client and the server. I'm serious. RPC handles get cached, and sometimes a service just trips over itself. A clean restart clears those stale handles.

• Restart the machine showing the error (client).
• Restart the remote server too, if you can.

If the error goes away, you're done. If not, move to Step 2. Don't skip this – it works about 30% of the time.

Step 2 – The 5-Minute Fix: Check DCOM Permissions

This is the real fix in most cases. The client doesn't have permission to create an RPC context on the server. That's why the handle comes back null.

Here's how to fix it on the server:

1. Open Component Services (run dcomcnfg as admin).
2. Go to Component Services > Computers > My Computer.
3. Right-click My Computer and choose Properties.
4. Click the COM Security tab.
5. Under Access Permissions, click Edit Default.
6. Make sure ANONYMOUS LOGON and Everyone have Remote Access allowed. If they're missing, add them.
7. Do the same under Launch and Activation Permissions – Edit Default. Add ANONYMOUS LOGON and Everyone with Remote Launch and Remote Activation allowed.
8. Click OK and close everything.

Now restart the server. Try your app again. This fixes the problem for most people, especially with SQL Server or custom apps that use RPC.

Step 3 – The 15+ Minute Fix: Reset RPC Service and Registry

If DCOM permissions didn't do it, the RPC service itself might be corrupted or misconfigured. This is rare but happens after a bad update or third-party firewall tweak.

First, reset the RPC service via command line:

net stop RpcSs && net stop RpcEptMapper
net start RpcEptMapper && net start RpcSs

Run those as admin on the server. That restarts the endpoint mapper and the RPC service cleanly.

Still broken? Check the registry. I've seen a bad entry in HKLM\Software\Microsoft\Rpc cause null handles. Back up the key first, then look for any weird subkeys added by third-party tools (like antivirus or monitoring agents). Delete them, but only if you're sure they're not default.

Last resort: Reinstall the RPC client on the client machine. That means the app that's calling the RPC. For SQL Server, that's the SQL Native Client. For Exchange, it's the MAPI client. Uninstall and reinstall it. Then reboot both sides.

When to Call Microsoft

If none of that works, check Windows Event Logs on both machines for related errors (like RPC_E_ACCESS_DENIED or RPC_S_SERVER_UNAVAILABLE). That usually points to a firewall block or a missing SPN for Kerberos. But those are separate articles. For this specific null context error, the steps above should get you running again.

Good luck – you've got this.