I was logging into the sever chosencraft and then it exited the minecraft page and went back to the minecraft launcher saying there was a problem

Put the summary of the bug you're having here

*What I expected to happen was it would log me in and I could continue play on my smp world.
Describe what you thought should happen here

*What actually happened was it didn't log in and exited the page and tookme back to the minecraft launcher
Describe what happened here

Steps to Reproduce:
Put a step by step guide on how to trigger the bug here
1. add server chosen craft ip: play.chosencraft.com
2. log into the server
3.it will redirect you to the minecraft launcher