When I join any server, the screen turns a light blue and then leads to the crash report screen in the launcher after about a second and a half. This has happened to me since this morning (6/22/16, 10am).
To recreate this, use version 1.10.1. After the title screen appears, click on multiplayer and then load up any server. The screen then crashes.
A temporary fix for this is to go back to version 1.10.0.

First crash is at the Hypixel server,
second is the US Mineplex.