Windows Media Encoder config file version mismatch fix

When this error hits

You're sitting in front of Windows Media Encoder 9 Series (or an older version like 8 or 7). You've downloaded a preset profile—maybe a high-quality streaming config for H.264 or a custom XML file from a forum. You go to File > New Session, pick Custom encoding session, then try to import that profile file. That's when the error slams you: The supplied configuration file is not supported by this version of the encoder. Error code 0XC00D1B8B. The session won't load.

I've seen this most often when someone grabs a profile designed for Windows Media Encoder 9 Series (the 32-bit one) but tries to open it in the 64-bit version of WME 9. Or when they use a config created for WME 10 or 11 (which doesn't exist as a standalone app, but the profiles got updated inside Expression Encoder). The XML inside the file has a version number your copy of WME doesn't understand.

Root cause, plain and simple

Windows Media Encoder stores encoding settings in XML files. Inside that XML, near the top, there's a line like <WindowsMediaProfile version="9.0">. If your encoder version is older than that number, it doesn't know how to handle the newer features. It throws the version mismatch error. The encoder isn't broken—it's just refusing to use a config that might reference codecs or settings it can't support.

The real fix isn't complicated. You need to edit the XML file by hand and change the version number to match your encoder's version. Or, even simpler, you rebuild the profile from scratch using the encoder's own wizard. I'll show you both ways, but the manual edit is faster if you only have one file to fix.

Fix: Edit the config file's version number

Before you start, make a backup copy of the .prx or .xml file. Put it somewhere safe.

1. Open the config file in Notepad. Don't double-click it—that might try to open it in the encoder. Right-click the file, choose Open with, pick Notepad (or any plain text editor like Notepad++).
2. Look at the first few lines. You'll see a line that starts with <WindowsMediaProfile and has a version attribute. It'll look like this: <WindowsMediaProfile version="9.0"> or <WindowsMediaProfile version="10.0">.
3. Change the version number to match your encoder. If you're using Windows Media Encoder 9 Series, change it to version="9.0". If you're using version 8, change it to version="8.0". If you're not sure what version you have, open the encoder, go to Help > About to see the version number.
4. Save the file. File > Save. Keep the same name and extension.
5. Try loading it again. In Windows Media Encoder, go to File > New Session > Custom encoding session. Click Import (or Browse depending on your version) and select the edited file.
6. Check the result. You should see the profile load without the error. If it still fails, the file might reference a codec your encoder doesn't have installed. That's a different problem—skip to the final section below.

After you change the version, the encoder reads the XML and maps the settings to what it knows. It might drop some newer features (like advanced deinterlacing options in a version 10 profile), but the basic bitrate, frame size, and codec settings will work.

Alternate fix: Rebuild the profile manually

If editing XML feels sketchy, or if the file has other issues, build a new profile from scratch:

1. Open Windows Media Encoder. Choose File > New Session > Custom encoding session.
2. In the Session Properties window, go to the Source tab and set your input file or device.
3. Go to the Output tab. Under Encoding options, click Edit.
4. In the Custom encoding settings dialog, tweak the video and audio settings to match what the original config file had. Write down the values from the old file (bitrate, resolution, frame rate, codec).
5. Give the profile a name and click Save Profile. Save it as a .prx file somewhere easy to find.
6. Now load that new profile whenever you need those settings.

This method always works because you're creating a profile that matches your encoder's exact version. The downside is you have to manually re-enter every setting. I only do this when the XML edit doesn't fix things.

What to check if it still fails

If you changed the version number or rebuilt the profile and the error still shows up, you've got one of these issues:

• Missing codec. The profile might use Windows Media Video 9 Advanced Profile (WVC1) or VC-1, which older encoders don't have. Check your system: do you have the Windows Media Video 9 VCM installed? If not, download it from Microsoft's archive (if still available) or use a simpler codec like Windows Media Video 9 Standard.
• Corrupted file. Sometimes a download gets truncated. Open the file in Notepad and check if the XML ends with </WindowsMediaProfile>. If not, you got a partial file. Re-download it.
• Wrong encoder version altogether. Windows Media Encoder 9 Series has both 32-bit and 64-bit versions. Profiles created for 64-bit sometimes have different internal references. If you're on 64-bit, try the 32-bit version instead—or vice versa. You can install both on the same machine.
• File extension tricks. Some profile files are actually .prx (which is just XML with a different extension). If you double-click a .prx file and it opens in the encoder, but the error appears, rename it to .xml and edit the version as shown above. Then rename it back to .prx. I've seen this fix odd read errors.

That's the whole deal. Nine times out of ten, changing the version number inside the XML kills the error. The remaining one time is usually a missing codec or a corrupted download. You've got this.