The d3dx9_31.dll file is one of many files contained in the DirectX software collection. Since DirectX is utilized by most Windows-based games and other advanced graphics programs, these errors usually show up only when using these programs.

D3dx9_31.dll Errors

There are a number of different errors involving d3dx9_31.dll, any one of which may show up on your computer. These are just some of the more common DLL error messages you might run into:

D3DX9_31.DLL Not FoundD3dx9_31.dll not found. Reinstalling might help fix thisFile d3dx9_31.dll not foundThe file d3dx9_31.dll is missingD3DX9_31.DLL is missing. Replace D3DX9_31.DLL and try againMissing component d3dx9_31.dllThis application has failed to start because d3dx9_31.dll could not be found

It’s important to understand the context during which the error occurs in order to properly fix it. For example, you don’t want to troubleshoot a missing DLL error for a video game if your error is related to a graphics editing program. The d3dx9_31.dll error message could apply to any program that utilizes Microsoft DirectX, but it’s most commonly video games, and it typically appears when the game is started. In non-game applications, this error might appear when the program starts or before graphics features of the program are used. Some common games and other programs that have been known to generate d3dx9_31.dll errors include Tom Clancy’s Rainbow Six, Battlestations: Midway, Vanguard: Saga of Heroes, Supreme Commander, Star Wolves 2, NeonDS (a Nintendo DS emulator), Autodesk Inventor Professional, Hospital Tycoon, Spider-Man 3, Halo 2, Transformers, and more.

How to Fix D3dx9_31.dll Errors

Need More Help?

If you’re not interested in fixing this problem yourself, see How Do I Get My Computer Fixed? for a full list of your support options, plus help with everything along the way like figuring out repair costs, getting your files off, choosing a repair service, and a lot more. This error might be a one-time issue, and a simple restart could clear it up completely. It’s unlikely this will fix the problem, but restarting is always a good first step with nearly any problem. Sometimes, though not often, the version included on the disc is a better fit for the program than the latest version available online.