An existing connection was forcibly closed by the remote host / NetworkDispatcher exception

Hello, i was trying to play with friends and mods, but we got a problem. my friends are not able to connect to my minecraft forge server, i've tryed everything but nothing works. we are using forge-1.12.2-14.23.5.2847, a month before the problem, we were playing without any issue. something strange about this is the fact that i can connect to my server using another computer with the same internet connection. we use hamachi for large distance connection, it is not a mod problem, we tried without mods and we got same problem from server. Here is the latest log form my server files, i execute the server with 4GB - Ram. I've deactivated the firewall and i do not have any antivirus, my friends too. also we tried with different versions of forge, same problem. :C

any hero there?

latest.log