No audio device available in audio configuration (Windows 10)

I am not able to select a main out device from the drop down menu in the “configure audio device” section. It’s empty.

When I’m closing Djay Pro the window is gone but the process stays up for quite a while and I’m not able to kill the process manually. After a while it disappears.

Already reset the application as well as reinstalled it from the Microsoft Store.

I’ld appreciate any help.

OS: Windows 10 Pro, with the big April 2018 update