I need help fixing this, please!

09.05 11:56:11 [Server] Netty Epoll Server IO #2/ERROR [Minecraft]: [ProtocolLib] INTERNAL ERROR: Unable to intercept a read client packet.
09.05 11:56:11 [Server] INFO If this problem hasn't already been reported, please open a ticket
09.05 11:56:11 [Server] INFO at https://github.com/dmulloy2/ProtocolLib/issues with the following data:
09.05 11:56:11 [Server] INFO Stack Trace:
09.05 11:56:11 [Server] INFO java.lang.RuntimeException: Error occured while instancing generated class.
09.05 11:56:11 [Server] INFO at com.comphenix.protocol.reflect.compiler.StructureCompiler.compile(StructureCompiler.java:237)
09.05 11:56:11 [Server] INFO at com.comphenix.protocol.reflect.compiler.CompiledStructureModifier.withTarget(CompiledStructureModifier.java:132)
09.05 11:56:11 [Server] INFO at com.comphenix.protocol.events.PacketContainer.(PacketContainer.java:128)
09.05 11:56:11 [Server] INFO at com.comphenix.protocol.injector.netty.ProtocolInjector.onPacketReceiving(ProtocolInjector.java:312)
09.05 11:56:11 [Server] INFO at com.comphenix.protocol.injector.netty.ChannelInjector.decode(ChannelInjector.java:594)
09.05 11:56:11 [Server] INFO at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:411)
09.05 11:56:11 [Server] INFO at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:248)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
09.05 11:56:11 [Server] INFO at com.comphenix.protocol.injector.netty.ChannelInjector$2.channelRead(ChannelInjector.java:290)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
09.05 11:56:11 [Server] INFO at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:293)
09.05 11:56:11 [Server] INFO at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:280)
09.05 11:56:11 [Server] INFO at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:396)
09.05 11:56:11 [Server] INFO at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:248)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
09.05 11:56:11 [Server] INFO at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
09.05 11:56:11 [Server] INFO at net.minecraft.network.LegacyPingHandler.channelRead(SourceFile:94)