It wont let me on any versions of 1.7.10 and lower, creating a crash page not letting me on my favorite server

Put the summary of the bug you're having here

What I expected to happen was...:
It would let me on the 1.7.10 server

What actually happened was...:
It brought me onto a crash page and wouldn't let me on the server

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...