I went to preference and there is not uncheck so that lightbox will not show at start up. when I try to go to open or close to the right of the light box button, it disappears.
¿¿¿ LOL … Maybe you better post some pictures because this doesn’t make much sense. What version of ZBrush are you using? Please post a full screenshot of your interface with the Preferences:Lightbox submenu open.