Server problem for mod 4.87

me and my family play on our own server. But it will not stay open when we start it. Can not remember what was told to us for 4.86 mod. but that worked. can anyone help us with this problem please. what happens when we try to play on our server is it shows up then it disappears about a second later. what can we do to remedy this problem. we had the same issue from 4.86. any help would be greatly appreciated please and thank you