It works for a while, but since some point, the sound never stops unless you close the project.
Is anybody in the same boat?

 

You should at least say what DAW (I assume you are using it in a DAW, because you mention closing the project.)
Also you should test the stand-alone...

[edit: Spent about 45 minutes playing with it, loading various groups and it didn't get stuck for me.
Kontakt 6.4.1 Portable + Fl Studio 20.6.2 build 1549.

 

Last edited: Sep 2, 2020

DAW doesn't matter. I tried it in Reaper and Studio One, and the result was the same.
Kontakt Portable 6.2.2 + Reaper 6.13 and Studio One 4.6.2

Wait! Kontakt 6.4.1 Portable? As long as I know, the latest portable version is 6.2.2 though.

 

U will find it on sister site ;)

 

Aha, thx!

 

I have the same/similar issue
Try playing legato patches on left hand, and countermelody on right one at the same time
You'll get a bug in which notes that you play 'll never stop
Not sure what's the issue though.

 

I found it could be the issue of Kontakt. When I installed the latest version, it said "
WHATS NEW:
6.4.1 — 2020-09-01

• FIXED Certain libraries (Cinematic Studio Strings and others) could cause incorrect long release notes under certain conditions"
  
  Let's see what will happen.
  

 

Good man, thank you
I'll install new kontakt version later on today, tbh if it says that in patch/notes, it's most likely fixed

 

Interesting your daw doesn't have a MIDI panic button/reset MIDI, or equivalent.

 

Kontakt itself have that button ...i am using it when i use ETHNAUDIO libraries<have same bug as OP mentioned

 

Where is the button? I've never heard that.

 

@Hennessey As you can see I quoted the op and was actually talking to the op, @Wolfang.
Your answer is unrelated to my comment to the op, to do with daws.