I'm running the BlendLuxCore-v2.1alpha1-win64.zip version.
When i cancel render the blender is at Canceling... and the windows blue circle is spinning. CPU is stuck at 8% for 10 minutes, is it doing something?
Denoiser is disabled.
Can you reproduce it every time or does it only happen sometimes (in the same scene)?
Does it happen with other scenes?
Can you upload a scene that shows the problem?
Tested simple cube scene same lighting and resolution. I hit the cancel and the refreshing film text comes up and then the render is canceled.
So my scene must be bad, it's polygon heavy maybe that's it (for blender 20-30 GB and when i start render then another 50GB).
You could try to open the console before you render (in Blender, Window -> Toggle System Console).
In the console there is more information printed about what's actually happening.
Try looking what happens there when you cancel the render in this heavy scene.
(By the way, do I understand correctly that the scene consumes about 80 GB of RAM in total during the render? Do you have enough RAM installed, or is the system swapping?)
The scene is using 80GB yes and i have 128GB installed.
When i cancel the render the Blender memory use drops below 4GB and is stuck at there CPU at 6-8 %, this is little strange because when i open blend file the memory use is 30GB. No swapping, PC is very much responsive.
Didn't see anything suspicious in console and the render canceled successfully this time, no glue what is going on.
Anyways the blender ui feels snappier with latest blendluxcore build.