As you advised before i do not touch the normal slot when adjusting a material while VFB running but, if i modify diffuse or everything else its just crashes… C4D R21 bug has been reported before.
Can u fix this issue please ? Its makes ppl nervous when adjusting pbr mats. 
Thanks: Levi
Hello Levi,
I was not aware that the issue was spread to other parameters (other than from the normal shader). I have bumped up the priority on this.
By the way, it is not necessary to create a forum post with every daily build, we’ll let you know in the changelog once we fix this 
Thanks,
Jan