Fix 0XC00D106B: Invalid ASX Loop Block in WMP

You're looking at 0XC00D106B — and yeah, it's a pain

This error pops up when Windows Media Player tries to read an ASX playlist file and finds a loop (REPEAT) block that's broken. Maybe you copied a playlist from an old forum post, or a podcast feed got mangled. Let's fix it.

The quick fix: edit the ASX file

ASX files are plain XML text. Open the file in Notepad (right-click > Open with > Notepad). Look for the REPEAT block. A valid REPEAT block looks like this:

<ASX version="3.0">
  <REPEAT>
    <ENTRY>
      <REF href="http://example.com/song1.wma"/>
    </ENTRY>
  </REPEAT>
</ASX>

If you see something like <REPEAT> without a matching </REPEAT>, or the <ENTRY> tag is missing a closing </ENTRY>, that's your problem. Delete the whole REPEAT block if you don't need looping, or fix the tags.

Common mistake I see: <REPEAT COUNT="0"> — WMP chokes on that. Remove COUNT entirely or set it to a positive integer like 1. Also check for mismatched quotes or extra spaces inside tags.

Why this happens

Windows Media Player parses ASX files using a strict XML parser. The error 0XC00D106B specifically means the REPEAT element contains something it can't interpret — maybe an unclosed tag, an invalid child element, or a duplicate attribute. I've seen it when someone hand-edits an ASX file and accidentally deletes a closing bracket.

ASX version 3.0 is the most permissive, but even then, the REPEAT block only allows ENTRY and ENTRYREF children. If you threw a <TITLE> or <ABSTRACT> inside REPEAT, WMP will reject it. Move those outside the REPEAT block.

Less common variations

REPEAT inside a nested REPEAT

WMP doesn't support nested loops. If you have a REPEAT inside another REPEAT, flatten them. Either merge them into one REPEAT block or remove the inner one.

Bad ENTRYREF with a REPEAT

If you use <ENTRYREF href="partial.asx"/> inside a REPEAT block, the referenced file itself might have a broken loop. Open the referenced ASX file and check its REPEAT block too.

Special characters in URLs

Ampersands in URLs (like &) need XML escaping. If your REF href contains & and you wrote it as & instead of &, the parser fails. That can trigger this error if it happens inside a REPEAT context.

Prevention tips

Use a playlist generator — I recommend VLC to export ASX files. Its output is clean and avoids these edge cases.
Validate ASX with an XML checker — Paste your ASX into a site like xmlvalidation.com before dropping it into WMP. Saves you time.
Avoid hand-editing — If you must, always save a backup. One missing > can ruin your morning.
Stick to version 3.0 — Older ASX versions (1.0, 2.0) are more forgiving with errors but I've seen them cause other weird behavior. Version 3.0 is the safest.

If the error still won't go away, delete the entire REPEAT block and see if the playlist loads. If it does, rebuild the loop from scratch — copy a known-good REPEAT structure from Microsoft's ASX documentation. That's saved my bacon more than once.