If you are seeing this message upon starting the launcher, it means this file has not been located and you may need to install or repair the DirectX 9.0c Runtime.
If you do not wish to see this message, navigate to Options in the launcher, and disable the "Check for XInput" option.
If this error message persists then you may need to repair your system files.
Please see Microsoft's guide on using the System File Checker tool to repair missing or corrupted system files.
If you believe you are seeing this and you do have DirectX 9.0c installed, please contact the support team via the button below with an attached Dxdiag report and let them know.