There used to be a setting in the General Preferences > Documents tab to auto-delete all but the latest thumbnail next time Poser is launched, but it is no longer there. The other setting, Launch to Preferred Scene, is still there and I keep it checked so my preferred launch is of a blank preview window. On the next tab, Interface, I have tried both Launch to Previous State and Launch to Factory State with no difference made. I also cleared the Undo Cache and reset the Temp files. Still no change. Was this setting removed in 11.2? I get tired of having to manually delete a dozen or more render thumbnails each time I launch... heck -- I don't even know where Poser is finding these images as none of them were saved and so no longer exist on my HDD!