The issue lies in the com.comphenix.protocol.injector.StructureCache.getStructure method, where the type parameter is null, causing the Preconditions.checkNotNull method to throw a NullPointerException.

[nate981120]

java.lang.NullPointerException: type cannot be null at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:907) at ProtocolLib.jar//com.comphenix.protocol.injector.StructureCache.getStructure(StructureCache.java:138) at ProtocolLib.jar//com.comphenix.protocol.events.PacketContainer.(PacketContainer.java:126) at ProtocolLib.jar//com.comphenix.protocol.injector.netty.manager.NetworkManagerInjector.onPacketSending(NetworkManagerInjector.java:96) at ProtocolLib.jar//com.comphenix.protocol.injector.netty.channel.NettyChannelInjector.processOutbound(NettyChannelInjector.java:553) at ProtocolLib.jar//com.comphenix.protocol.injector.netty.channel.NettyChannelInjector$2.doProxyRunnable(NettyChannelInjector.java:456) at ProtocolLib.jar//com.comphenix.protocol.injector.netty.channel.NettyEventLoopProxy.proxyRunnable(NettyEventLoopProxy.java:43) at ProtocolLib.jar//com.comphenix.protocol.injector.netty.channel.NettyEventLoopProxy.execute(NettyEventLoopProxy.java:252) at net.minecraft.network.Connection.sendPacket(Connection.java:449) at net.minecraft.network.Connection.send(Connection.java:392) at net.minecraft.server.network.ServerConnectionListener.tick(ServerConnectionListener.java:243) at net.minecraft.server.MinecraftServer.tickChildren(MinecraftServer.java:1586) at net.minecraft.server.dedicated.DedicatedServer.tickChildren(DedicatedServer.java:446) at net.minecraft.server.MinecraftServer.tickServer(MinecraftServer.java:1393) at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1170) at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:317) at java.base/java.lang.Thread.run(Thread.java:840)

[JH3Y50N]

i too same problem.

[Ingrim4]

Please use the latest dev build and try again: https://ci.dmulloy2.net/job/ProtocolLib/. Error should be fixed in latest build