Fix NS_E_CURL_INVALIDURL (0XC00D1329) error in Windows Media Player

What's triggering this error?

This error usually pops up when you try to open a streaming URL or a local file link in Windows Media Player (WMP) and the player can't parse the address. I've seen it most often with older playlists (.wpl, .asx) that have broken URLs, or when someone pastes a link with typos like http// missing the colon. Another common trigger: a URL that includes spaces or special characters that aren't encoded.

Don't panic. We'll start with the 30-second fix and escalate only if you need to.

The 30-second fix: Check the URL format

This sounds obvious, but it's the fix for 8 out of 10 cases. Open the file or playlist that's causing the error and look at the URL.

1. Right-click the .wpl or .asx file and pick Open with > Notepad.
2. Find the line that looks like <ref href="..."/> or just the URL inside the file.
3. Make sure it starts with http:// or https:// — never http// or http:/. Even one missing slash breaks it.
4. If the URL has spaces, replace them with %20. For example, http://example.com/my file.mp3 should be http://example.com/my%20file.mp3.
5. Save the file and try opening it again in WMP.

If the error's gone, you're done. If not, move to the next fix.

The 5-minute fix: Re-register Windows Media Player components

Sometimes the issue isn't the URL itself — it's WMP's URL parser getting corrupted. I've fixed this on dozens of Windows 10 and 11 machines by re-registering a few DLLs.

1. Close WMP completely.
2. Open an administrator command prompt (search cmd in Start, right-click, choose Run as administrator).
3. Run these commands one by one:
   

   regsvr32 /i wmp.dll
   regsvr32 /i wmnetmgr.dll
   regsvr32 /i wmadmod.dll
   regsvr32 /i wmpdxm.dll

4. You'll see a success message for each one (or an error if a DLL is missing, which is rare).
5. Reboot your PC and test the link again.

This re-registers the core networking and parsing components WMP uses to handle URLs. Works especially well if the error came after a Windows update or a codec pack installation. If it still fails, we've got one more trick.

The 15-minute fix: Check registry for broken URL associations

This is for the stubborn cases — when the URL looks perfect and the DLLs are fine, but WMP still throws the error. The culprit is often a corrupted registry key that tells Windows how to handle certain URL protocols (like mms:// or rtsp://).

Warning: Messing with the registry can break stuff. Back it up first (File > Export in regedit).

1. Press Win + R, type regedit, hit Enter.
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media Player\Setup.
3. Look for a value named ErrorMode. If it exists and is set to 1, double-click it and change it to 0. This tells WMP to show more detailed error info — sometimes that helps you spot the real issue.
4. Next, go to HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player.
5. Delete any keys that look like URL_* — these are cached URL parsing rules that can go stale. Don't delete the whole Player key, just the URL-specific ones.
6. Close regedit, restart your PC, and test.

This worked for a client who had a corrupted mms:// handler after installing a third-party media app. If none of these help, the URL itself might be dead — test it in a browser first. If the browser can't open it, the server is the problem, not your PC.

Pro tip from my help desk days: I always keep a text file with common URL patterns handy. Copy-paste is your friend — one mistyped character in a playlist can waste 20 minutes of debugging. Use Notepad++ with URL highlighting to spot errors fast.

That's it. Start with the URL check, move to the DLL re-register, and only go to the registry if you have to. You'll beat this error in under 15 minutes max.