I’m getting this too, I just updated from v9 to v10 hoping for a fix but it’s showing the same behaviour. I’ve tried the suggestion on the previous page of replacing the null blend mask with T_White but this doesn’t do anything, if I then drop T_White into the Blend Mask in the Chameleon BP it breaks it completely (no effects visible) and I have to revert the Structures to get it working again.