Actually an issue with poser since 13 may be also 12 who knows, for sure this issue has already been mentioned a few times but ignored on updates. allot of features are broken in the render engines I guess it will take them quiet a while sorting it all out. just use export image instead of the "Tear off" function then you will not get a blank Png, same with preview renders they can only be saved using the export feature. The Tear Off is totally messed up ....