Where in the world is d3dx9_43.dll?

If you're getting an error telling you that "d3dx9_43.dll" is missing from your computer, and you're unable to start a match of League of Legends, here's how to fix it.

The League of Legends client can certainly be a glitchy experience, but this error isn't one of the many that is on Riot Games' side of the equation. As the error states, if you're getting this specific error code, your computer is missing a specific Direct X file. Here's how to get that file and why you might be getting the error.

How to fix "d3dx9_43.dll" missing error in LoL

The "d3dx9_43.dll" file is one of the files in the DirectX gaming API, and it can be missing from your computer for a few plausible reasons. Importantly, this error is 100% something wrong on your PC, not with Riot's servers or client.

Firstly, this applies if you have a new computer that you're just getting set up, or if you have a computer that you haven't updated in a while or freshly restarted. The first thing you should try to do is fully update Windows. The default updates for Windows should include this file, so updating the OS directly should install the file automatically. You'll have to restart to update Windows anyhow, so fire back up the League of Legends client afterward and see if it works.

Olaf (Image via Riot Games)
Olaf (Image via Riot Games)

If that didn't solve it, you'll have to go get the file manually. Luckily, DirectX makes exactly this quite easy. You'll have to download DirectX End-User Runtime, which can be freely downloaded from Microsoft. Once you've installed it, you can manually force updates and install DirectX files. You should be able to easily install the file where it needs to go with this program. These are the only two official solutions that Riot Games offers, so if they don't solve it, you'll have to file a ticket with player support.

That's everything you should need to know about this DirectX error and how to solve it.