Dolphin Emulator on Arch crashing when launching a game

I am running the latest version of Arch with the (newest) git version of dolphin, but every time I try to run a game it crashes with:

ALSA lib pcm_dmix.c:1099:(snd_pcm_dmix_open) unable to open slave
terminate called after throwing an instance of ‘std::system_error’
what(): Das Argument ist ungültig //Translation: Invalid argument

Does aynbody know how to fix this error?

Have you tried installing alsa-utils and alsa-plugins ?

Yes, they are already installed.