I cant connect to my friends server I used to be able to but i cant now but i can connect to other servers i literally tried pretty much everything neither of us know how to fix it it is really irritating as we were going to make a lets play series and if i cant connect then we cant really do it has anyone have any ideas????????????????????

PPLLLLLLLLEEEEAAASSSSSSSSEEEEEEE HHEEEEELLLLLLLPPPPPPP!!!!!!!!!!!!!!!!!!!!!!!