Windows 7
Windows 7 support has been deprecated since Update 2.20, and now with Update 2.22 we fully dropped support.
The missing DLL is xaudio2_8.dll. XAudio can be downloaded from NuGet, and its 2_9redist.dll in there, can be renamed to 2_8.dll and placed in the Game folder to work around that issue. But you may end up without Game Sound.
We plan on creating a wiki page to document how to do that, but it won't last long until we make more changes that don't support Windows 7.
Please consider not using a Operating System who's support ended 6 years ago.
You can switch to the Legacy Branch (Find the access code here) to play the 2.20 version which still works on Windows 7.