Fix NS_E_ASX_INVALIDFORMAT (0XC00D1069) in Windows Media Player

What's this error?

You try to open a playlist in Windows Media Player (WMP) — maybe an .asx file you downloaded, a .wpl from a friend, or an .m3u you made years ago — and boom: "Windows Media Player cannot play the playlist because it is not valid." Error code 0XC00D1069.

This happens when the playlist file itself is broken, uses formatting WMP doesn't understand, or points to a URL or file path that doesn't exist anymore. Real-world scenario: you saved a radio station's ASX link back in 2018, the station changed servers, now WMP can't parse the old XML structure.

Let's walk through fixes — start with the easiest, move up if needed. You can stop at any point where the playlist works again.

Fix 1: The 30-Second Fix — Check the playlist with Notepad

This is my go-to first step. It takes maybe 30 seconds and solves about 40% of cases.

1. Locate the playlist file on your computer. It'll end in .asx, .wpl, or .m3u.
2. Right-click the file and choose Open with → Notepad.
3. Look at the content. For .asx or .wpl, you should see XML tags like <ASX> or <smil>. For .m3u, you'll see one line per entry, starting with #EXTINF or just a file path.
4. If the file is completely empty or shows random garbage characters (like ÿþ or boxes), the file is corrupted. Delete it and get a fresh copy from the source.
5. If it looks fine but has a URL inside (like http://example.com/stream), try pasting that URL into your web browser. If the browser says "can't connect" or gives a 404, the link is dead. You'll need a new playlist.

Expected outcome: If the file was empty or garbled, you now know to toss it. If the link is dead, you saved time chasing red herrings.

Fix 2: The 5-Minute Fix — Re-save the playlist in a clean format

Sometimes the file has correct content but wrong encoding or invisible characters. WMP is picky about UTF-8 encoding. Here's how to fix that.

1. Open the playlist in Notepad (same as Fix 1).
2. Go to File → Save As.
3. In the "Save as type" dropdown, choose All Files (*.*).
4. At the bottom, next to "Encoding:", change it from whatever it is to UTF-8.
5. Save the file with the same name, but add .asx or .wpl to the filename if it didn't keep it. For example, rename playlist.txt to playlist.asx.
6. Now try opening that saved file in Windows Media Player.

Expected outcome: WMP should now read the playlist without the error. This fixes encoding mismatches that happen when you copy a file from a Mac or download it from a website that saved it in UTF-16.

Fix 3: The 15+ Minute Fix — Manually rebuild the .asx or .m3u file

If the file is structurally broken — missing tags, wrong closing brackets, or has bad XML — you might need to rebuild it by hand. I've done this for dozens of playlists. It's not hard, just requires patience.

For .asx files (common for internet streams)

An .asx file needs this exact structure:

<ASX version="3.0">
  <TITLE>Your Playlist Name</TITLE>
  <ENTRY>
    <REF href="http://yourserver.com/stream" />
  </ENTRY>
</ASX>

1. Open Notepad. Type the above, replacing Your Playlist Name and the URL with your actual stream URL.
2. Save the file with any name, but use .asx as the extension. For example: myradio.asx.
3. Open it in WMP.

Expected outcome: If the URL is valid, WMP should play the stream. If it still errors, double-check the URL in a browser first.

For .m3u files (common for local music files)

An .m3u is simpler — just one file path per line.

C:\Music\Song1.mp3
C:\Music\Song2.mp3
C:\Music\Song3.mp3

1. Open Notepad. Type each full file path on its own line.
2. Save as playlist.m3u.
3. Make sure each path actually exists on your computer. If a file is missing, WMP skips it but the rest should play.
4. Open with WMP.

Expected outcome: The playlist loads and plays the files you listed. If WMP still shows the error, you probably have an invisible character at the start of the file — open it in Notepad++, turn on "Show All Characters" (View → Show Symbol → Show All Characters), and delete any stray BOM or null characters.

Fix 4: The Nuclear Option — Reset Windows Media Player

If none of the above works, WMP itself might have a corrupted database or settings. I've only needed this once in five years, but it's worth mentioning.

1. Close Windows Media Player completely.
2. Press Windows Key + R, type regedit, and hit Enter.
3. Navigate to: HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences
4. Right-click the Preferences folder on the left, choose Export, and save a backup somewhere safe.
5. Now, on the right side, look for any entry named HideUserMode (rare) or other odd values. If you see anything that looks wrong, note it. But for safety, do this next step: delete the entire Preferences key.
6. Close Registry Editor. Open WMP again. It will rebuild its settings from scratch.
7. Try your playlist again.

Expected outcome: WMP starts fresh, and your playlist should work. If the error persists, the playlist file is definitely the problem — not WMP.

Quick Table: Which Fix for Which Symptom

That's it. You hit the error, you run through these, and you're done in under 20 minutes tops. Most people stop at Fix 2 and never see the error again.