Since installing update 1.8 all I get when I open Minecraft on my mac is a black screen, I can hear music but nothing comes up on screen. Also can not exit without shutting computer off completely.

Duplicate of MC-21603. This is a bug with older versions of OSX, and occurs when minecraft does in fullscreen. To reset your settings, in the game launcher, click "Edit Profile" -> "Open game dir" and then delete the optiions.txt file.

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