Quick answer: This error occurs when the WMS HTTP Download Data Source plugin receives data exceeding its internal buffer limit. The fix is either to increase the plugin's buffer size via the registry or to split the source file into smaller chunks.
If you're running Windows Media Services (commonly on Windows Server 2008 R2 or 2012) and see this error pop up when trying to stream content via the HTTP Download Data Source plugin, you're not alone. I've seen this on setups where the media file is unusually large — say, over 200 MB for a video file — or when the metadata in the file (like embedded album art or chapter markers) bloats beyond what the plugin expects. The plugin was designed for smaller, efficiently packed data containers, and it trips over oversized payloads. The exact trigger: a file served through the plugin that exceeds the default data container size limit (usually around 256 KB for the text container). This isn't a network issue — it's a buffer boundary inside the plugin itself.
How to Fix the 0XC00D1589 Error
Step 1: Increase the Plugin's Buffer Limit via Registry
The cleanest fix is to raise the buffer limit for the HTTP Download Data Source plugin. This is a registry tweak that tells the plugin to accept larger data containers. Here's how:
- Open Regedit as Administrator (Win + R, type
regedit, right-click and run as admin). - Navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media\WMServer\Plugins\HTTP Download Data Source - If the HTTP Download Data Source key doesn't exist, create it manually under the Plugins key.
- Create a new DWORD (32-bit) value named
MaxDataContainerSize. - Set its value in bytes. For a 1 MB limit, use
1048576(decimal). I usually set it to2097152(2 MB) for most scenarios. Don't go over 10 MB unless you have a specific reason — the plugin get unstable with huge buffers. - Click OK, close Regedit, and restart the Windows Media Services service: in an admin command prompt, type
net stop wmserver && net start wmserver.
Step 2: Verify the File Isn't Corrupt
Before blaming the plugin, check the source file. This error can also fire if the WMS HTTP Download Data Source plugin received a malformed data container — like an ASF or WMV file with broken metadata headers. Use Windows Media Encoder or a tool like ASF Viewer to inspect the file. If it throws warnings about "invalid object size" or "corrupt data unit extensions," the file is the problem. Re-encode the file using Windows Media Encoder 9 or higher with default settings for WMV/ASF — that usually fixes it.
Step 3: Split the File Into Smaller Chunks
If increasing the buffer didn't work or you can't modify the registry (locked-down server), break the file apart. For a 500 MB video, split it into 100 MB segments using a tool like FFmpeg with segment muxing. Then host the segments on your WMS server and update your playlist or player to handle sequential chunks. It's more work, but it sidesteps the limit entirely.
Alternative Fixes When the Main One Fails
Switch to a Different Data Source Plugin
The HTTP Download Data Source plugin isn't your only option. Try the WMS Multicast Data Writer plugin or WMS Pull Plug-in instead. These don't enforce the same container size limit. On your WMS server, go to Properties > Allow new plug-ins, then add the pull plugin. Point it to the same file — it'll stream it differently and likely bypass the error.
Disable the Plugin and Use Static HTTP Streaming
If you're in a pinch, ditch the plugin entirely. Host the file on IIS with the right MIME types (like .wmv for video/x-ms-wmv) and let Windows Media Player pull it directly over HTTP. The player can handle larger files natively — the plugin was just a middleman causing the bottleneck.
Preventing This Error in the Future
Set a hard limit on file size in your media pipeline. Anything over 150 MB should be re-encoded with minimal metadata — strip out extra album art, embedded scripts, and large chapter markers. Use Windows Media Encoder's Optimize for streaming preset. Also, monitor your WMS logs for the Event ID 0XC00D1589 — if it appears, you'll know a file is too fat before users complain. Automate a script that checks file container sizes against a threshold (say, 200 KB for ASF header objects) and flags outliers.
This error is annoying but fixable. Start with the registry tweak — it's saved my bacon on more than one server. If that fails, the file itself is likely the culprit, not the plugin.