my game wont let me log into minecraft after the 1.6.1. update came out

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
for me to log into minecraft
What actually happened was...:
Describe what happened here
it said the game crashed and won't ever let me play minecraft
Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...log into account
3. ... try to play mc