Fix NS_E_TOO_MANY_MULTICAST_SINKS Printer Error

I know that sinking feeling when your printer freaks out with this multicast error. It's vague, it's annoying, and it stops you from sharing the printer on the network. But the fix is straightforward — you've got two multicast data writer plug-ins enabled on the same publishing point, and Windows won't allow that.

The Quick Fix: Disable the Extra Multicast Plug-in

You'll need to dig into the Windows Media Services console. Even if you never set up Windows Media Services, it often gets installed alongside printer sharing tools. Here's how to shut down the duplicate:

Press Win + R, type services.msc, and hit Enter. This opens the Services window.
Scroll down to Windows Media Services. Right-click it and select Stop. After stopping, right-click again and choose Properties.
In the Properties window, set the Startup type to Disabled. Click Apply, then OK.
Now open an admin Command Prompt. Press Win + X and choose Command Prompt (Admin) or Windows Terminal (Admin).
Type this command and press Enter:
```
sc delete "WMServer"
```
This removes the Windows Media Services service entirely. You'll see a success message: [SC] DeleteService SUCCESS.
Reboot your computer. After restarting, check if the printer publishes correctly. If you're still seeing the error, move to the next section.

After disabling the service and deleting it, you should be able to publish your printer without that error. I've seen this fix work on Windows 10 version 22H2 and Windows 11 version 23H2. The key is that the printer's publishing point now has only one multicast data writer plug-in active — the one from the printer driver itself.

Why This Error Happens

Here's the technical reason: Windows Media Services installs a multicast data writer plug-in for streaming content. When you enable printer sharing via multicast DNS (mDNS) or WS-Discovery, the printer driver also creates its own data writer plug-in on the same publishing point. The error code 0xC00D1456 literally means NS_E_TOO_MANY_MULTICAST_SINKS — only one multicast data writer plug-in is allowed per publishing point. The system detects two and throws the error.

In my experience, this happens most often after a Windows update or printer driver update. The update re-enables Windows Media Services, or a new driver version adds its own multicast support, causing the conflict. The real fix is to remove one of them, and Windows Media Services is almost always the unnecessary one.

Less Common Variations of This Error

Sometimes the error persists even after disabling Windows Media Services. Here are three other scenarios I've run into:

Third-Party Multicast Software

If you have software like VLC Media Server, Plex Media Server, or Twonky Media Server installed, they can also create multicast data writer plug-ins. Check your installed programs list. Uninstall any media server software you don't use. If you do use one, check its settings for multicast publishing and disable it — just for the printer's publishing point.

Corrupted Printer Driver

I've seen a corrupt printer driver create a phantom multicast plug-in that doesn't show up in the console but still conflicts. Open Control Panel > Devices and Printers. Right-click your printer and select Remove device. Then restart your PC, and reinstall the latest driver from the manufacturer's website — not Windows Update. I prefer HP Universal Print Driver for HP printers, and the manufacturer's own driver for others. This clears out any stale plug-in registrations.

Group Policy Lockdown

On corporate networks, a Group Policy might enforce Windows Media Services being enabled. If you can't disable it via Services, check your local Group Policy. Run gpedit.msc as admin, go to Computer Configuration > Administrative Templates > Windows Components > Windows Media Services. Look for any policy that says Windows Media Services is set to Enabled. If it is, set it to Not Configured and run gpupdate /force from an admin command prompt. Then try the Service disable again.

Preventing This Error From Coming Back

Once you've got it fixed, here's how to keep it from returning:

Never install Windows Media Services manually. It's not needed for printer sharing. If a Windows update tries to add it, uninstall the update via Settings > Update & Security > View update history > Uninstall updates.
Always use the printer manufacturer's driver. The generic Microsoft driver sometimes bundles extra multicast support. Specific drivers from Canon, HP, Brother, or Epson are leaner and less likely to conflict.
Keep a restore point. Before any major update, create a system restore point. If the error comes back after an update, you can roll back quickly.
Monitor your Services list. If you see Windows Media Services re-enabled, stop and disable it again immediately. I do a quick check every few months.

That's it. You shouldn't see error 0xC00D1456 again. If you do, revisit the variations above — it's almost always a plug-in conflict. Print on, friend.