I need help. I just got my Mac a while ago, and I don't know tons about Mac. My computer has never had a problem with uploading anything before. It would always open the window (Finder?), I would select the file, and it would upload it. Today, it just stopped letting that window open. It will flash the window for a second, and then it would disappear. It's not hiding behind the safari window, nor is it in any of my spaces. I've tried restarting my computer, and resetting everything that I know to reset in Safari (pop up settings, cookies, cache, etc.). Any ideas?