Put the summary of the bug you're having here
MInecraft crashes upon startup after trying to update in Mac OSX (Mavricks)

What I expected to happen was...:
The game to update and start

What actually happened was...:
game appeared to update, produced error page

Steps to Reproduce:
1. started client normally
2. logged in, screen went black, few seconds later error screen popped up
3. restarted client
4. forced update in case files were not downloaded correctly
5. repeat of step 2
6. started game with terminal, adding extra memory as done in past to increase performance( java -Xmx2000M -Xms2000M -jar minecraft.jar)
7. repeat of step 4
8.repeat of step 2