Cannot connect to Realms

I try to connect to any of my friends' Realms, and it either tells me "Cannot Connect to World" or does this really weird glitchy screen then goes back to the Realms menu. I have a video showing this, as I can't get a screenshot of it properly.

https://drive.google.com/file/d/0BwmgcyGJq36cRTl3M0ZPQldraHc/view?usp=drivesdk