Rocket League is not launching on Windows N
If you are running Rocket League on Windows version N, this can be fixed by downloading and installing the Windows Media Pack.
Verify the Windows Version
Right-click the Windows Icon in the lower left corner.
Select System.
Navigate to Windows Specifications.
On the Edition line look for an N in the Windows version.
Download and Install the Windows Media pack
To download and install the correct version of the Windows Media Pack check out this Microsoft article: Media Feature Pack for Windows N (Opens in a new tab)