Online Game Error - NEED HELP!

HI,

I am hoping someone is able to help, as i am losing my mind with this and also with the lack of a solution……

I started an online game with my mate the other day. All was going well ,we played for a good few hours, then obviously called it a night before we both became singled off from our Mrs's….Any way, went to load the game up the day after (and every subsequent day), to us both being greeted with the same message when we load the game up: ‘Unable to connect to server’………..Can anyone….someone, please let me know how I/we may  be able to rectify this and get our game going again??

Many thanks in advance!!