Having my first major Mac Pro issue. I am currently locked out of my computer, and I haven't a clue how to get it back working. I think it's "bricked" but I can't be sure. I have recently installed Mavericks into my 5,1 Mac Pro, and ok'd the new icloud "keychain" and when working last night I had a freeze up in my System pref pane, (seemingly because of a hiccup in Hazel) that it would not display, as did my Finder somewhat. After running a repair permissions finder was still frozen as was system pref pane. I set the mac to reboot before bed, and whatever caused the freeze up had the mac not complete its reboot cycle as it remained where I left it last night. Hung. So I did a manual power down, and reset the PRAM hinting this would fix the situation. Unfortunately when the Mac booted up I was presented with this login screen that does not accept my password. just grey with a default icon and states "update needed". I have tried just about everything to bring it back, but nothing seems to work. It boots, and before the keyboard can register for me to go into recovery mode it defaults to this screen. It stays like that for about five minutes then shuts itself off again. I even removed the boot drive, and it still get the screen, I am out of options. Do I need to shop for a new mac, or is there a fix for this. Edit: many posts I have read stated that it could be the cause of FileVault. Unfortunately, it isn't turned on.