i always crash right after i join a server or join a single player world it won't stop please help me it won't let me play minecraft. this also is happening to my friends

Put the summary of the bug you're having here

What I expected to happen was...:
it to be fixed after the second time
What actually happened was...:
it just kept crashing and crashing and crashing

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