So I am not technologically gifted, so here it goes. i have seen others have the problem where something along the lines of this pop up "The last time Lightroom ran, it shut down prematurely due to a problem reading the catalog. Lightroom must now check the catalog before proceeding." and I read that it had to do with a preview cache being saved by my normal catalog? Most people in other threads said it needed to be moved, renamed and then manually redone in lightroom. Does anyone have a step by step process to fix it?