Server closing upon joining

Me and my friend are playing on a server and we have a modpack, but whenever i join the server closes either immediately or after 10 seconds. We made a new server and it happened again, we just get the "This server is closed" screen and get kicked out. Please help, here is my log :

What do you mean by share?

Here it is

It works,thanks. I think there will be no further errors but i will make a thread if so.