Crash: Ticking screen 'java.lang.NullPointerException: Ticking screen'

Summary:
Everytime I have internet and I refresh at the multiplayer screen to check my ping, my minecraft freezes and if I have no internet connection, it crashes.

What I expected to happen was...:
Just for the client not to crash.

What actually happened was...:
The client crashed.

Steps to Reproduce:
1. I have no internet connection.
2. I must have had internet connection beforehand and used the multiplayer screen to check ping before
3. I refresh at the multiplayer screen with no internet connection to check ping
4. There is a pause instead of the servers showing up either showing the ping or that there's not connection
5. If I don't press cancel and go to the home menu, the client will stay frozen for a little longer, then crash.