Steve, my 05_Cactus.veg was not write protected, it was checked "archive" like the other *.veg files. I have deleted the cactus files, then I could install. Now the volumetric spotlight problem is resolved. But I cannot use any of my plants having leaves or grass. For all the others, I get the message "cannot read *.prv". This means I get black trees. I have deleted the "vegetation.prv", but this did not help. No plants, no Vue. Can I do something else ? Thanks, Guitta