HI Tom, thanx for the Response. 

Iam with AU here. During Playback Ableton is working fine, when trying to automate  some parameters, yes, Blackholes GUI update it self very slowly.  

“When you say that the sound vanishes completely after stopping playback, do you mean that the reverb tail suddenly stops?”

I meant that the whole GUI of the Blackhole Freezes during Playback, and Unfreezes only when i stop Playback and the Reverb Tail is completly gone. 

I must mention that today for example i opened the BlackHole again and everything seemed to work fine. Weird, i didnt re-install or do anything different. 

Iam happy now, but what could it be if it happens again? 

I will try on the up coming days to mess aruond with it and i will let you know how it goes.

Thanx again

Kevin