Fehlermeldung - Server - im Leerlauf

CLIENT 1 CHANGE STATE: Connected -> Disconnecting
CLIENT 1 CHANGE STATE: Disconnecting -> Disconnected
REMOVE: de.jiw.network.server.session.ClientConnection@7920a7d1 - 1 - 
0
14.02.2018   14:22[TcpSessionHandler ExceptionCaught] /192.168.178.128:54075   
F.f
[TcpSessionHandler ExceptionCaught] /192.168.178.128:54108INFO
: [TcpSessionHandler ExceptionCaught] /192.168.178.128:54125Delete Client ID: 1


[TcpSessionHandler ExceptionCaught] /192.168.178.128:54026
SERIALIZER: CLASS NOT FOUND 4212
io.netty.handler.codec.DecoderException: java.lang.IllegalStateException: Class not found
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:98)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	at io.netty.channel.nio.AbstractNioMessageChannel$NioMessageUnsafe.read(AbstractNioMessageChannel.java:93)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
	at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
	at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalStateException: Class not found
	at de.jiw.network.core.codec.serializing.Serializer.getClass(Serializer.java:126)
	at de.jiw.network.core.codec.UdpProtocolDecoder.decode(UdpProtocolDecoder.java:35)
	at de.jiw.network.core.codec.UdpProtocolDecoder.decode(UdpProtocolDecoder.java:11)
	at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:88)
	... 15 more
... (1) ChunkAdditions saved to DB!
... (1) ChunkAdditions saved to DB!