Multiplayer on Minecraft PE not working?

Okay I enter a server in and when I enter it it said "You are not authenticated anymore" what does that mean? I can't move around all I do is jump up and down. I really want to play multi player on minecraft PE help?

Minecraft PE has been having ALOT of bugs because putting a huge server on an Iphone wasn't a smart idea for mojang. Hopefully the next update will help this problem!

Hm, it looks like the server requires you to authenticate your account which can be done by logging in. If you first joined the server and had to /register, try to /login (insert password here). If you did not register, try to /register and "create an account" on the server. If you still can't authenticate yourself, contact the server's staff for assistance.

Minecraft multiplayer is not showing the local multiplayer severs and the Wi-Fi is on and the local multiplayer switch is on