I'm building a custom modpack, and I got a multimob crash while switching dimensions. I jumped in the Twilight Forest portal, and while the dimension was loading, there was an error with MultiMob. It'd be awesome if you could fix this!

Here's the full log:
latest.log

And here's the "short" version of the error:
[19:47:23] [Netty Server IO #1/ERROR]: There was a critical exception handling a packet on channel multimob
java.lang.NullPointerException: null
at net.daveyx0.primitivemobs.message.MessagePrimitiveJumping$Handler.onMessage(MessagePrimitiveJumping.java:44) ~[MessagePrimitiveJumping$Handler.class:?]
at net.daveyx0.primitivemobs.message.MessagePrimitiveJumping$Handler.onMessage(MessagePrimitiveJumping.java:34) ~[MessagePrimitiveJumping$Handler.class:?]
at net.minecraftforge.fml.common.network.simpleimpl.SimpleChannelHandlerWrapper.channelRead0(SimpleChannelHandlerWrapper.java:56) ~[SimpleChannelHandlerWrapper.class:?]
at net.minecraftforge.fml.common.network.simpleimpl.SimpleChannelHandlerWrapper.channelRead0(SimpleChannelHandlerWrapper.java:36) ~[SimpleChannelHandlerWrapper.class:?]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) ~[SimpleChannelInboundHandler.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:108) ~[SimpleChannelInboundHandler.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102) ~[MessageToMessageDecoder.class:4.1.9.Final]
at io.netty.handler.codec.MessageToMessageCodec.channelRead(MessageToMessageCodec.java:111) ~[MessageToMessageCodec.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) ~[DefaultChannelPipeline$HeadContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) ~[DefaultChannelPipeline.class:4.1.9.Final]
at io.netty.channel.embedded.EmbeddedChannel.writeInbound(EmbeddedChannel.java:274) ~[EmbeddedChannel.class:4.1.9.Final]
at net.minecraftforge.fml.common.network.internal.FMLProxyPacket.processPacket(FMLProxyPacket.java:99) [FMLProxyPacket.class:?]
at net.minecraft.network.NetworkManager.channelRead0(NetworkManager.java:147) [gw.class:?]
at net.minecraft.network.NetworkManager.channelRead0(NetworkManager.java:49) [gw.class:?]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [SimpleChannelInboundHandler.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.handleServerSideCustomPacket(NetworkDispatcher.java:452) [NetworkDispatcher.class:?]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.channelRead0(NetworkDispatcher.java:264) [NetworkDispatcher.class:?]
at net.minecraftforge.fml.common.network.handshake.NetworkDispatcher.channelRead0(NetworkDispatcher.java:72) [NetworkDispatcher.class:?]
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:105) [SimpleChannelInboundHandler.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) [DefaultChannelPipeline$HeadContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [AbstractChannelHandlerContext.class:4.1.9.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) [DefaultChannelPipeline.class:4.1.9.Final]
at io.netty.channel.local.LocalChannel.finishPeerRead0(LocalChannel.java:443) [LocalChannel.class:4.1.9.Final]
at io.netty.channel.local.LocalChannel.access$500(LocalChannel.java:49) [LocalChannel.class:4.1.9.Final]
at io.netty.channel.local.LocalChannel$5.run(LocalChannel.java:397) [LocalChannel$5.class:4.1.9.Final]
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) [AbstractEventExecutor.class:4.1.9.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403) [SingleThreadEventExecutor.class:4.1.9.Final]
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:442) [NioEventLoop.class:4.1.9.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [SingleThreadEventExecutor$5.class:4.1.9.Final]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_51]