NS_E_MULTIPLE_VBR_AUDIENCES (0XC00D1BB5) fix

Quick answer for pros

Open your encoding profile (or script) and change all VBR audiences to CBR. Or remove the "multiple bitrate" flag and keep a single VBR stream. Either way, you can't have both MBR and VBR in the same file.

What's this error really about?

This error shows up when you're using Windows Media Encoder 9 Series, Windows Media Format SDK, or any tool that builds Windows Media files (.wmv, .wma) with multiple bitrate audiences and variable bitrate encoding. The exact message is NS_E_MULTIPLE_VBR_AUDIENCES (0XC00D1BB5): "It is not possible to use MBR encoding with VBR encoding."

I've seen this most often when someone tries to create a streaming file for Windows Media Services with multiple bitrate versions (like a low, medium, and high bitrate for adaptive streaming) but sets each to VBR instead of CBR. Windows Media doesn't support that combo. It's not a bug — it's a design limitation in the Windows Media codec architecture. The MBR system expects constant bitrate streams so it can switch between them smoothly. VBR throws that off because the bitrate bounces around unpredictably.

You'll also trigger this if you use third-party encoding tools (like Expression Encoder, ffmpeg with the ASF wrapper, or old Adobe Premiere plugins) that let you pick both options at once without warning you they can't coexist.

Fix steps

1. Identify which tool or script is doing the encoding.
   If you're using Windows Media Encoder 9, open the session file (.wsx or .wme) in Notepad. If you're using a custom program with the Windows Media Format SDK, look for IWMProfile::CreateNewMutualExclusion calls or IWMStreamConfig::SetBitrate lines in your code.
2. Check each audience in the profile.
   In Windows Media Encoder, go to the Session Properties —> Compression tab. You'll see a list of audiences (bitrate settings). If any of them say "VBR" in the codec name (like "Windows Media Video 9 VBR"), that's your problem.
3. Change VBR audiences to CBR.
   Select each audience that uses VBR, click Edit, and pick the CBR (constant bitrate) version of the same codec. For example, pick "Windows Media Video 9" instead of "Windows Media Video 9 VBR". After changing each one, click Apply. You should see the audience list update to show no VBR codecs.
4. If you can't switch to CBR (say you need VBR quality), remove the multiple bitrate mutual exclusion.
   In Windows Media Encoder, uncheck the "Allow multiple bitrate streams" checkbox on the Compression tab. This tells the encoder to output a single stream at a fixed bitrate (the highest one you configured). After unchecking, click Apply. The error should go away.
5. Test the encoding.
   Start encoding. The process should run without the 0XC00D1BB5 error. If it still fails, double-check that all audiences are CBR now.

Alternative fixes if the main steps don't help

• Use a different tool. Windows Media Encoder 9 is old and clunky. Switch to Expression Encoder 4 (free, still downloadable from Microsoft's archive) or use ffmpeg with the -c:v wmv2 -b:v 2000k -maxrate 2000k -bufsize 4000k flags. That forces CBR and bypasses the MBR/VBR confusion entirely.
• Rebuild the profile from scratch. Sometimes profiles get corrupted. In Windows Media Encoder, go to Session Properties —> Compression —> New. Create a fresh CBR-only profile with one audience. Save it. Then load that into your session.
• If you're coding with the SDK, check your mutual exclusion flags. Look at the WM_MEDIA_TYPE and WM_STREAM_TYPE_INFO structures. Make sure you're not calling SetVBRMode on any stream that's part of a multiple bitrate exclusion. The fix is to either remove the exclusion or set all streams to CBR.

Prevention tip

Before you start any Windows Media encoding job, decide upfront: do you need adaptive streaming with multiple bitrates? If yes, always use CBR for every audience. If you need VBR quality, stick to a single stream — no multiple bitrate option. Mark that profile as "single bitrate" so you don't forget later. I've seen teams waste hours on this because the profile template said "VBR" and nobody checked.