I had the exact same problem (create game button does nothing). I had to disable all mods in a skirmish started via the .exe from programdata. For me, it was not the AI Wave Survival mod though! I had M27AI on, but disabling that alone was not enough.

Thanks for workaround, still hope for fix!

This is an old issue, there are some posts on this if you look deeply.
Seems to be an issue with DirectX.
Either
deactivate sound card in BIOS - unplug or the like and reactivate on next boot (needs to boot into Windows once)
or
uninstall the sound card driver and reboot (and perhaps install after next reboot if necessary)

I did the latter when I lost my sound a few days ago. Also had this issue a few years ago, too.