I want to play Minecraft on version earlier than 1.8, but it won't let me

Put the summary of the bug you're having here

What I expected to happen was that I could log in to the hub.thenexusmc.com so I could play on the server.

What actually happened was I watch the screen as it says 'logging in' then all of a sudden I CRASH! AND IT HAPPENS ALL THE TIME!!!!

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