Why can't I hear any sound in Preview 5?

I have updated the engine to Preview 5 and I noticed that no sound is working now!
I have tried Tappy Chicken and Swing Ninja and the sound cues are not working there too!
I have tried the check button (enable Sound on Editor Preferences) but it also doesn’t make any difference!
What is going on?

Hey

There are some known issues such as sound in Preview 5. You can find always the newest known Issues also in the Forum for each of the Previews. Here you go Unreal Engine 4.7 Preview - Announcements - Unreal Engine Forums

Sad… I had some hope… now my deadline is gone…