after a horrendous first tryout of daz 4.15 which crashed 50% of the time (and forced a reinstall of the last version I had - 4.1208) I finally co installed the 4.15 beta so both could be used. It seems to crash less now but I am finding some unexpected changes with renders. I still use iray as render engine of choice (filament does seem better as a previewer) but I now find that with genesis 8.1 skins there is an interference pattern if you use caustics. This showed up clearly on a HD 8.1 character but also on other surfaces. The lighting used was one distant light. Is this a known problem?