I have created a new world with all the mods, when i start to place mod's blocks, the server begin to work abnormally and the client start lagging,if i place other mod's blocks the client start lagging heavily then he kick me with the same error.
Then i begin to delete the mods(first Blastcraft, second ICBM then Universal Electricity).
if i delete all the mods, the server/client stop lagging(obviously)but if i use one of those( Blastcraft and ICBM are addons of Universal Electricity, they can't work without it) the client crash...
I tried to give more ram(from 6 to 12Gb) to the server but nothing.
i have no idea how to resolve this problem, this isn't a specific error and i can't give you a crash report because...server and client don't crash...