Fix NS_E_NO_NEW_CONNECTIONS (0XC00D151D) streaming error

When this error hits

You're streaming a video from your Windows 7 or Windows 8 Media Center PC to an Xbox 360 or a DLNA player. Everything was working fine, then suddenly the stream stops. You get a pop-up: "The content cannot be played because the server is not currently accepting connections" with error code 0XC00D151D. Sometimes it happens when you try to start a second stream while one's already playing. Other times, it's after the PC's been running for days with a bunch of media sessions open. I had a client last month whose whole family couldn't watch their recorded TV shows on different Xboxes because of this.

What's really going on

Windows Media Center and the underlying Windows Media Player Network Sharing Service have a hard limit on how many simultaneous client connections they'll allow. By default, it's set to a low number—typically 5 or 10. Once that pool is full, any new connection gets slammed with error 0XC00D151D. The server doesn't say "busy, try later"—it just denies the connection outright. The root cause is almost always a stale connection that didn't close properly. A client's Xbox might have sent a disconnect signal, but the server still holds the slot open. After a few of those pile up, you hit the cap.

How to fix it

Step 1: Kill stale connections

Stop the service that's holding these dead sessions. Open an elevated Command Prompt (right-click Cmd.exe, Run as Administrator). Run these commands:

net stop WMPNetworkSvc
net start WMPNetworkSvc

That restarts the Windows Media Player Network Sharing Service. It clears all active sessions—good and bad. Your media server will come back up within 10-15 seconds. Test your stream immediately.

Step 2: Increase the connection limit (the real fix)

Restarting works temporarily, but you'll run into this again if you regularly have multiple clients. Bump the limit up so you don't hit it so easily. This requires a registry tweak.

Warning: Messing up the registry can break things. Back it up first or create a restore point.

1. Press Win + R, type regedit, hit Enter.
2. Navigate to:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Service\MediaServer\Connections
3. If Connections key doesn't exist, create it (right-click > New > Key).
4. Inside Connections, create a DWORD (32-bit) value named MaxConnections.
5. Double-click it, set Base to Decimal, enter a number between 10 and 20. I usually go with 15. Avoid higher unless you've got a server-class machine—it can affect streaming performance.
6. Close Regedit and restart the service again: net stop WMPNetworkSvc && net start WMPNetworkSvc.

Step 3: Check for stuck sessions (optional but helpful)

If you're still seeing the error, check if there are orphaned sessions. Open Task Manager (Ctrl+Shift+Esc), go to the Services tab, find WMPNetworkSvc. Note its PID. Then open an admin Command Prompt and run:

netstat -ano | findstr :10243

Port 10243 is the default WMC streaming port. If you see multiple connections from the same IP in ESTABLISHED state with the same PID, those are probably duplicate sessions from a client that reconnected. Restarting the service clears them. If it's a recurring issue, check if your router's UPnP settings are causing flaky connections.

What to check if it still fails

Sometimes the problem isn't the connection limit—it's deeper. If the error persists after bumping the limit and restarting the service:

• Firewall or antivirus: Some personal firewalls (looking at you, Norton) block multicast traffic after a few connections. Temporarily disable the firewall and test. If it works, add an exception for wmplayer.exe and ehshell.exe.
• Network profile: Windows needs the network set to Private to allow network discovery and media streaming. If it's on Public, the service won't accept new connections at all. Go to Settings > Network & Internet > Wi-Fi (or Ethernet) > click your network > set to Private.
• Multicast limits on your switch: If you're on a corporate or managed network, some switches limit IGMP multicast groups. This is rare at home, but if you're streaming from a work laptop, talk to your IT guy.
• Corrupted media database: If everything else fails, the media database that WMC uses to serve content might be corrupt. Stop the service, delete the database files from %LOCALAPPDATA%\Microsoft\Media Player (backup first), then restart the service. The database rebuilds automatically. Takes a few minutes.

In nine out of ten cases, the registry tweak alone solves it. If you're still stuck after all that, consider switching to a dedicated media server like Plex or Jellyfin—they handle simultaneous connections much better than WMC ever did.