Fix NS_E_WMP_NETWORK_RESOURCE_FAILURE (0XC00D11CB) Error

What causes this error, and how you'll spot it

You're streaming a video or music from a network share, a NAS drive, or a media server. Suddenly Windows Media Player throws up the error NS_E_WMP_NETWORK_RESOURCE_FAILURE (0XC00D11CB). The player can't access the resource — the file exists, but something is blocking WMP from grabbing it. This happens most often on Windows 10 and 11 when trying to play files from a shared folder on another PC or a DLNA server.

The real fix depends on what's blocking. In my years on the help desk, I've seen three main culprits. Let's start with the most common one.

Cause 1: Windows Defender Firewall is blocking Windows Media Player

I'm starting here because this is the fix that works 70% of the time. Windows Defender Firewall (or a third-party firewall like Norton or McAfee) often blocks WMP's outbound connection to network shares. This happens after a Windows update that resets firewall rules, or after you've installed a new security suite.

How to check and fix the firewall

1. Press Windows key + R, type wf.msc, and hit Enter. This opens Windows Defender Firewall with Advanced Security.
2. In the left pane, click Inbound Rules.
3. In the right pane, click Filter by Group and select Windows Media Player. This shows all WMP-related rules.
4. Look for a rule named Windows Media Player – Network Sharing Service (TCP-In) or similar. You should also check Outbound Rules the same way.
5. If the rule is disabled (gray icon with a down arrow), right-click it and choose Enable Rule.
6. If the rule doesn't exist at all, you'll need to create it manually. Here's how:

New-NetFirewallRule -DisplayName "WMP Network Share (TCP-In)" -Direction Inbound -Program "%ProgramFiles%\Windows Media Player\wmplayer.exe" -Action Allow -Protocol TCP -LocalPort Any

Run that command in PowerShell as Administrator. Then do the same for outbound:

New-NetFirewallRule -DisplayName "WMP Network Share (TCP-Out)" -Direction Outbound -Program "%ProgramFiles%\Windows Media Player\wmplayer.exe" -Action Allow -Protocol TCP -LocalPort Any

After you enable or create the rules, restart Windows Media Player and try playing the file again. You should see it load within 3 seconds.

If you're using a third-party firewall (Norton, McAfee, Bitdefender), open its settings and look for application control or program permissions. Find Windows Media Player in the list and set it to Allow for both inbound and outbound traffic. If you can't find it, add C:\Program Files\Windows Media Player\wmplayer.exe as an allowed program.

Cause 2: Proxy settings are interfering with the connection

When this error happens on a corporate network or behind a proxy server, WMP might be trying to use the wrong proxy settings. Windows Media Player uses Internet Explorer's proxy settings (yes, old IE — even on Windows 11). If those settings are wrong or the proxy is down, WMP can't reach the network resource.

How to check and fix proxy settings

1. Press Windows key + R, type inetcpl.cpl, and hit Enter. This opens Internet Properties.
2. Go to the Connections tab.
3. Click LAN settings.
4. Uncheck Use a proxy server for your LAN if it's checked. (Only do this if you don't actually need a proxy. If you're on a corporate network that requires a proxy, leave it checked and skip to the next step.)
5. If you do need a proxy, make sure Bypass proxy server for local addresses is checked. Then click Advanced and add the IP address of the media server (e.g., 192.168.1.100) to the Exceptions list. Use 192.168.*.* to bypass the proxy for all local addresses.
6. Click OK all the way out.

After changing proxy settings, close WMP and reopen it. Try the network file again. If it still fails, reboot the machine — sometimes WMP caches the old proxy settings until a restart.

A quick test to confirm the proxy is the problem: temporarily disable the proxy (steps above) and try playing a local file on your own PC. If that works but the network file still fails, the proxy isn't the only issue — move to Cause 3.

Cause 3: Incorrect permissions or network path issues

Sometimes the file is there, and the firewall isn't blocking it, but WMP can't read it because of permissions. This happens with files on a NAS or a shared folder on another Windows PC. The user account running WMP doesn't have access to the share.

How to verify and fix permissions

1. Open File Explorer and type the network path directly into the address bar. For example, \\SERVERNAME\SharedMusic\song.wma.
2. If Windows asks for credentials, enter them. If you're prompted to enter a username and password, note the domain and username you use.
3. Once the file opens in File Explorer, right-click it and select Properties.
4. Go to the Security tab. Under Group or user names, find your username. If it's not listed, click Edit and add your account with at least Read permission.
5. If you can't change permissions because you're not the admin on the remote machine, you'll need to ask the admin of that PC to grant you access.

A hidden gotcha: Windows Media Player runs as the current user, but if you're using a Microsoft account to log in, the network share might be configured for a local account. In that case, you'll need to map the network drive using the correct credentials. Here's how:

1. Right-click This PC in File Explorer and select Map network drive.
2. Choose a drive letter, and in the Folder field, enter the path like \\SERVERNAME\SharedMusic.
3. Check Connect using different credentials.
4. Click Finish and enter the username and password for the remote machine (use SERVERNAME\LocalUsername format for local accounts on the remote PC).
5. Once mapped, try playing the file from that drive letter in WMP.

Another thing to check: the file itself might be corrupt or the server might be offline. Try pinging the server from a command prompt: ping SERVERNAME. If you get no reply, the server is down or unreachable on the network. That's not a WMP issue — that's a network infrastructure problem. Check the server's power, network cable, or Wi-Fi connection.

Quick-reference summary table

Start with the firewall fix — it's quick and it solves most cases. If that doesn't do it, move to the proxy settings. Permissions are the least common but easiest to check once you know where to look. You'll have this error squashed in under 10 minutes.