D3dx9_31.dll Error Messages
There are a number of different errors involving d3dx9_31.dll, any one of which may show up on your computer. Some of the more common d3dx9_31.dll error messages are shown below:
"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!"
D3dx9_31.dll errors typically appear when a software program, usually a video game, is started.
In non-game applications, a d3dx9_31.dll error might appear when the programs starts or before graphics features of the program are used.
Cause of D3dx9_31.dll Errors
All d3dx9_31.dll issues are caused in one way or another by a single issue - a problem with Microsoft DirectX.
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, d3dx9_31.dll errors usually show up only when using these programs.
Important Note: Do not, under any circumstances, download the d3dx9_31.dll DLL file individually from any "DLL download site." There are a number of different reasons that downloading DLLs from these sites are never a good idea.
Note: If you've already downloaded d3dx9_31.dll from a DLL download site, remove it from wherever you put it and continue with the following steps.
Restart your computer if you haven't already.
The d3dx9_31.dll 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.
Install the latest version of Microsoft DirectX 9. Chances are, upgrading to the latest version of DirectX 9 will fix the d3dx9_31.dll not found error.
Note: Microsoft often releases updates to DirectX 9 without updating the version number or letter so be sure to install the latest release even if your version is technically the same.
Note: Are you a Windows Vista user with DirectX 10? Your game or program may still need DirectX 9 files to run properly so give the installation a try. Don't worry, both versions of DirectX can be run side by side in Windows Vista.
Assuming the latest DirectX version from Microsoft doesn't fix the d3dx9_31.dll error you're receiving, look for a DirectX installation program on your game or application CD or DVD. Usually, if a game or other program utilizes DirectX, the software developers will include a copy of DirectX on the installation disc.
Sometimes, though not often, the DirectX version included on the disc is a better fit for the program than the latest version available online.
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.
Restore the d3dx9_31.dll file from DirectX 9 software package. If the above steps haven't worked to resolve your d3dx9_31.dll error, try extracting the d3dx9_31.dll individually from the DirectX 9 software package.
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.
The d3dx9_31.dll error message could apply to any program that utilizes Microsoft DirectX, most commonly video games.
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.
Any of Microsoft's operating systems since Windows 98 may be effected by d3dx9_31.dll and other DirectX issues. This includes Windows 2000, Windows XP, Windows Vista, and Windows 7.