Fix NS_E_WSX_INVALID_VERSION (0XC00D151E)

NS_E_WSX_INVALID_VERSION – What You're Dealing With

This error pops up when Windows Media Services (WMS) tries to load a playlist file (.wsx) that has a version stamp it doesn't recognize. I've seen this on Server 2008 R2 and 2012, but it can appear on any version still running WMS. The culprit here is almost always a playlist file that was saved by a newer tool or edited by hand with a higher version number.

The error text says it all: The version of this playlist is not supported by the server. The server expects version 1.0, but the file claims something else. It's not a network issue, not a permissions issue – it's a format mismatch. Don't waste time checking firewalls or DNS. Go straight for the playlist.

Below I've laid out the fixes in order of effort. Start with the 30-second one, test, and only move on if it doesn't work.

Fix 1: Quick Fix – 30 Seconds

This is the fastest thing to try, and it works more often than you'd think. Open the playlist file in Notepad (or any text editor) and check the version attribute on the <smil> tag.

<?wsx version="1.0"?>
<smil>
  <body>
    <seq>
      <media src="file://C:/Media/song.mp3"/>
    </seq>
  </body>
</smil>

If you see version="1.1" or anything other than 1.0, change it to 1.0 and save. Then reload the playlist in WMS. That's it. The server only understands version 1.0, period. This fix takes 30 seconds and solves the problem if the version number was accidentally bumped.

If the version is already 1.0, move on to the next fix.

Fix 2: Moderate Fix – 5 Minutes

If the version is already 1.0, the problem is likely a corrupted or non-standard playlist structure. The server is picky about the XML format. Here's what I usually do:

Export the current playlist from WMS to a backup file. Right-click the playlist in the WMS console, select Export, and save a copy somewhere safe.
Delete the existing playlist from WMS.
Recreate the playlist from scratch using the WMS console, not by hand. Go to Publishing Points, right-click your publishing point, select Properties > Source, and click Change to create a new playlist.
Add your media files one by one, or use the Add Media button to point to a folder.
Save the new playlist and test.

This forces WMS to generate a playlist in the correct format. I've seen playlists that were copied from another server or edited in a third-party tool end up with extra attributes or namespace declarations that WMS chokes on. Rebuilding from the console strips all that garbage out.

Fix 3: Advanced Fix – 15+ Minutes

If rebuilding didn't help, or if you're dealing with a large playlist you can't recreate by hand, we need to get our hands dirty. The root cause is almost always a hidden character or malformed XML. Here's the methodical approach:

Step 1: Validate the XML

Open the .wsx file in Notepad++ or VS Code. Look for any weird characters – invisible Unicode, BOM marks, or stray quotes. The file should start with <?wsx version="1.0"?> exactly. No leading spaces, no BOM. If the file has a BOM (you'll see a ï»¿ at the start if you view it in a hex editor), strip it out. Save the file as UTF-8 without BOM.

Step 2: Check for Extra Attributes

Sometimes playlist editors add extra attributes to the <smil> tag, like xmlns or id. WMS doesn't like that. The <smil> tag should be bare – just <smil>. Any extra attribute is suspect. Remove them.

Step 3: Rebuild the File with a Script

If you have hundreds of media entries, hand-editing is a pain. Use a PowerShell script to regenerate the playlist from your media folder. This gives you full control over the XML output. Here's a rough script I've used:

$mediaFolder = "C:\Media"
$files = Get-ChildItem -Path $mediaFolder -Filter *.mp3 -Recurse

$content = @"
<?wsx version="1.0"?>
<smil>
  <body>
    <seq>
"@

foreach ($file in $files) {
    $uri = $file.FullName.Replace(' ', '%20')
    $content += "<media src=\"file://$uri\"/>`n"
}

$content += @"
    </seq>
  </body>
</smil>
"@

$content | Out-File -FilePath "C:\Media\playlist.wsx" -Encoding ASCII
Write-Host "Playlist regenerated."

Run this, then upload the new playlist to your WMS server and point the publishing point at it. This eliminates any hidden formatting issues because the script writes clean ASCII.

Step 4: Check WMS Version

If you're on an old WMS version (like the one in Server 2003), it might genuinely not support a newer playlist format. But since this error is version-specific, double-check your WMS version to ensure it's not an unsupported upgrade path. In most cases, the fix is the file, not the server.

Why This Happens

In my experience, this error usually happens after someone edits a playlist with a modern text editor that adds a BOM or changes the encoding, or after copying a playlist from a newer WMS version. The server is strict about the version attribute and the XML structure. It's not a fun error to debug, but once you know it's a file format issue, it's easy to fix.

One last tip: always keep a clean copy of a known-good playlist template handy. When you run into this error again — and you will — you can just compare or replace the broken file without thinking.