D3dx9_43.dll errors are caused by a problem with Microsoft DirectX.
How to Fix d3dx9_43.dll Missing Error for All Games and Apps in Windows
Restart your computer if you haven't already. The d3dx9_43.dll error may be a fluke and a simple restart may fix it completely.
Install the latest version of Microsoft DirectX. There is a good chance that upgrading to the latest version of DirectX will fix the d3dx9_43.dll not found error.
If the latest version of Microsoft's DirectX does not fix the d3dx9_43.dll error you are receiving, look for a DirectX installer on your game or application DVD or CD.