My friends and I recently purchased Tom Clancy’s Rainbow Six Siege from Steam. Unfortunately, none of us could play the game after installing it because of the d3dx9_31.dll is missing error. I found the whole thing wired considering the fact that I had never encountered any problem with any of the games from steam and our computer setup was the same. I reinstalled the game, but it didn’t solve anything. We decided to branch out in search of a solution because the plan was to play the game together. We tested a lot of solution guides, but we couldn’t get any viable solution. However, we discovered that the d3dx9_31.dll is missing or cannot be found error has nothing to do with the game, and the issue was with the operating system. I installed all the latest updates, updated my drivers, yet none of that could fix the d3dx9_31.dll is missing error. My friend finally discovered one guide which turned out to be the solution to our problem.
You can’t fix the d3dx9_31.dll is missing error by reinstalling the game because d3dx9_31.dll happens to be a system library. You can fix it either by manually installing the because d3dx9_31.dll library or reinstalling your system. I decided to go for the first solution – installing the because d3dx9_31.dll library manually. So I visited https://fix4dll.com/d3dx9_31_dll, and downloaded the d3dx9_31.dll file and installed it. However, you must first select the appropriate operating system then follow the instructions for your own operating system on the download page.