i play on the server nexus mc and whenever i die or spam click my sword it closes me out ccompletly

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
I would just die and respawn like before

What actually happened was...:
Describe what happened here
I was closed out of minecraft for some reason

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...so you play capture the flag on thenexusmc.net then you die or spam click something to get closed out
3. ...