How to fix server Time out?

Sponge : 3422

Error ,

[20:01:08] [Netty Server IO #9/ERROR] [FML]: NetworkDispatcher exception
java.io.IOException: An existing connection was forcibly closed by the remote host
at sun.nio.ch.SocketDispatcher.writev0(Native Method) ~[?:1.8.0_181]
at sun.nio.ch.SocketDispatcher.writev(Unknown Source) ~[?:1.8.0_181]
at sun.nio.ch.IOUtil.write(Unknown Source) ~[?:1.8.0_181]
at sun.nio.ch.SocketChannelImpl.write(Unknown Source) ~[?:1.8.0_181]
at io.netty.channel.socket.nio.NioSocketChannel.doWrite(NioSocketChannel.java:432) ~[NioSocketChannel.class:?]
at io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:856) [AbstractChannel$AbstractUnsafe.class:?]
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.forceFlush(AbstractNioChannel.java:368) [AbstractNioChannel$AbstractNioUnsafe.class:?]
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:618) [NioEventLoop.class:?]
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:559) [NioEventLoop.class:?]
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:476) [NioEventLoop.class:?]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:438) [NioEventLoop.class:?]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [SingleThreadEventExecutor$5.class:?]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_181]