NS_E_NO_SERVER_CONTACT (0XC00D00CE) – Quick Fixes

What's This Error?

You're seeing NS_E_NO_SERVER_CONTACT (0XC00D00CE) when Windows Media Player or another app tries to stream from a server. The app can't reach the server at all — not a timeout, not a bad response. The connection fails outright. On Windows 10/11, this usually hits when you're on a corporate network, VPN, or behind a strict firewall.

I've fixed this dozens of times. The culprit here is almost always one of three things: a misconfigured firewall, DNS resolution failure, or a proxy server that doesn't play nice with streaming protocols. Let's work through them from quickest to deepest.

The 30-Second Fix: Check Your Firewall

Before you touch anything else, check if Windows Firewall or a third-party firewall (like Norton, McAfee, or your corporate VPN client) is blocking the app. This is the most common cause.

1. Press Windows Key + R, type wf.msc, hit Enter.
2. In the left pane, click Inbound Rules.
3. Click Outbound Rules too — streaming traffic goes outbound.
4. Look for any rule blocking wmplayer.exe or iexplore.exe (if using IE/Edge with Media Player plugin). Disable or delete the blocking rule.
5. If you have a third-party firewall, temporarily disable it. Does the error go away? If yes, add an exception for Windows Media Player (usually C:\Program Files\Windows Media Player\wmplayer.exe).

Real-world trigger: Corporate firewalls often block RTSP (port 554) and MMS (port 1755) outbound. If you're on a work VPN, the VPN client's firewall might kill these ports. Check with your IT team if disabling the firewall works but you can't keep it off.

The 5-Minute Fix: DNS and Proxy Settings

If the firewall isn't the issue, DNS resolution is the next suspect. The server hostname isn't resolving to an IP address. Or your proxy is intercepting the request incorrectly.

Flush DNS Cache

ipconfig /flushdns
ipconfig /registerdns
netsh winsock reset

Run those three commands in an elevated Command Prompt (right-click, Run as administrator). Reboot the app. If the error's gone, great — you had a stale DNS entry.

Check Proxy Settings

Windows Media Player can use Internet Explorer's proxy settings. If you're behind a proxy, it might not handle streaming protocols (RTSP, MMS) correctly.

1. Open Internet Options (Control Panel > Internet Options).
2. Go to the Connections tab, click LAN settings.
3. Uncheck Use a proxy server for your LAN — but only temporarily for testing. If the error disappears, you need to configure the proxy to bypass streaming servers. Add the server's domain or IP to the Exceptions list (like *.streaming.example.com).

Skip the proxy bypass for local addresses checkbox — it rarely helps with this specific error.

The 15+ Minute Fix: Registry Tweaks and Protocol Handling

If you're still stuck, the problem might be a corrupted protocol handler or a registry setting that forces Windows Media Player to use the wrong network stack. I've seen this after a Windows update that overwrote media foundation components.

Reset Media Foundation

regsvr32 wmnetmgr.dll
regsvr32 wmpshell.dll
regsvr32 wmadmod.dll
regsvr32 wmvdecod.dll

Run those as administrator. Restart the app. This re-registers the core streaming DLLs.

Force IPv4 (if you're on a broken IPv6 network)

Some networks have IPv6 enabled but broken DNS for IPv6. This can cause NS_E_NO_SERVER_CONTACT because the app tries IPv6 first, fails, and doesn't fall back to IPv4. You can disable IPv6 on the network adapter:

1. Open Network and Sharing Center > Change adapter settings.
2. Right-click your active connection, choose Properties.
3. Uncheck Internet Protocol Version 6 (TCP/IPv6).
4. Click OK, reboot. Test the stream.

Don't leave IPv6 disabled permanently unless you're sure you don't need it — but for this test, it's safe. If the error goes away, contact your network admin about IPv6 DNS configuration.

Registry Edit: Protocol Handler Order

This is the nuclear option. Windows Media Player uses a list of protocol handlers to decide how to connect. If the RTSP or MMS handler is missing or corrupted, you get this error.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MediaPlayer\Player\MLS\ProtocolHandlers

Check that rtsp and mms are present. Each should have a default value pointing to wmnetmgr.dll. If missing, create a new key for each protocol (type REG_SZ) with value wmnetmgr.dll. Reboot the app.

I've only needed this registry fix twice in 14 years — but both times it was the silver bullet.

Still Failing? Check the Server Side

If all the above fails, the server might be down or misconfigured. Try accessing the stream URL from a different device on a different network (like your phone on cellular). If it works there, the problem is your network. If it fails everywhere, the server's the issue — contact the stream provider.

One last thing: some corporate networks use SSL inspection that breaks non-HTTPS streams. If you see the error specifically for RTSP streams (rtsp://), ask your IT team to whitelist that protocol from inspection. It's a long shot, but I've seen it.