Put the summary of the bug you're having here
What I expected to happen was...:
i was gonna play a server
What actually happened was...:
minecraft crashed and brought me to a crash report
Steps to Reproduce:
1. i do not know how to
2. ?
3. ?
Related issues
Comments

There's a bug in Minecraft 1.10.1 that crashes your game when connecting to servers.
See MC-103981 and MC-103978 for more info.
In the meantime, you can safely downgrade to 1.10 until a proper fix is released.
To change your game to a different version, start the launcher. Select Edit Profile.
In the "Use Version" dropdown menu, select the game version you want. Then click Save Profile.