How to Fix D3dx9_31.dll Not Found or Missing Errors

If installing DirectX doesn't fix the problem, reinstall the program or game that's producing the error

All d3dx9_31.dll issues are caused in one way or another by a single issue: a problem with Microsoft DirectX.

This 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.

Any of Microsoft's operating systems since Windows 98 may be affected by d3dx9_31.dll and other DirectX issues. This includes Windows 11Windows 10Windows 8Windows 7, etc.

D3dx9_31.dll Errors

d3dx9_31 DLL error message

There are a number of errors involving d3dx9_31.dll, any one of which may show up on your computer as an error message like one of the following:

  • D3DX9_31.DLL Not Found
  • D3dx9_31.dll not found. Reinstalling might help fix this
  • File d3dx9_31.dll not found
  • The file d3dx9_31.dll is missing
  • D3DX9_31.DLL is missing. Replace D3DX9_31.DLL and try again
  • Missing component d3dx9_31.dll
  • This 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, Sims 3, Transformers, and more.

How to Fix D3dx9_31.dll Errors

Follow these steps in the order they're given below to try the simpler solutions first.

Do not, under any circumstances, download this DLL file individually from any DLL download site. There are a number of reasons why doing that is never a good idea. If you've already done so, remove it from wherever you put it and continue with the following steps.

  1. Restart your computer if you haven't already.

    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.

  2. Install the latest version of Microsoft DirectX. Chances are, upgrading to the latest version will fix the d3dx9_31.dll not found error.

    Microsoft often releases updates to DirectX without updating the version number or letter, so be sure to install the latest release even if your version is technically the same.

  3. Assuming the latest DirectX version from Microsoft doesn't fix the error you're receiving, look for a DirectX installation program on your game or application CD or DVD. Usually, if a game or another program utilizes DirectX, the software developers will include a copy of it on the installation disc.

    Sometimes, though not often, the version included on the disc is a better fit for the program than the latest version available online.

  4. Uninstall the game or software program and then reinstall it again. Something might have happened to the files in the program that work with d3dx9_31.dll, and a reinstallation could do the trick.

  5. Restore the file from the latest DirectX package. If the above steps haven't worked to resolve your error, try extracting the file individually from the DirectX software package.

  6. Update the drivers for your video card. While it's not the most common solution, in some situations, updating the drivers for the video card in your computer could correct this DirectX issue.

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