Unable to Join Friends Worlds

Since last night, me and my friend are unable to join each others personal worlds. Every time I try to join a friend's worlds the game displays " Unable to Connect to World". 

Further more, the problem started when me and my friends were in one of my friend's world and suddenly the game kicked all of us out of the world except the owner of the world, after that we are unable to join to other worlds. 

 

please provide a solution as soon as possible. 

thank you 

Muhammad Kalantan.