I was having problems with safari constantly quitting then I installed firefox and it kept quitting. I don't think that is the problem what is going on now, but just gonna mention that in case it helps. Now after I tried to install Lightroom, my computer started to freeze up and now finder doesn't work. The upper panel in finder doesn't work either. Can't open any folders, nothing seem to work. when i click on the finder or safari it goes to a blue blinking screen and then goes back. I tried to back up but of course it gave me errors. Please, if anyone knows what could be possibly wrong with it, let me know. Thank you.