Need Help. Game crashed, now I can't connect to my server.

[kastleking12]

I joined a dimensional doors portal, then my game crashed.  After restarting my client, I get an error when trying to connect to my server.  

Here is what my log says. 

2017-04-23 21:08:11 [INFO] Done (0.853s)! For help, type "help" or "?" 2017-04-23 21:08:15 [INFO] kastleking12[/127.0.0.1:54423] logged in with entity id 86 at (3499.5, 9.0, -1827.5) 2017-04-23 21:08:15 [INFO] Disconnecting kastleking12 [/127.0.0.1:54423]: Internal server error 2017-04-23 21:08:15 [WARNING] Failed to handle packet for kastleking12 [/127.0.0.1:54423]: java.lang.NullPointerException java.lang.NullPointerException at net.minecraft.server.management.ServerConfigurationManager.func_72355_a(ServerConfigurationManager.java:120) at net.minecraft.network.NetLoginHandler.completeConnection(NetLoginHandler.java:194) at cpw.mods.fml.common.network.FMLNetworkHandler.handleClientConnection(FMLNetworkHandler.java:166) at cpw.mods.fml.common.network.FMLNetworkHandler.onConnectionReceivedFromClient(FMLNetworkHandler.java:120) at net.minecraft.network.NetLoginHandler.func_72529_d(NetLoginHandler.java:178) at net.minecraft.network.NetLoginHandler.func_72532_c(NetLoginHandler.java:71) at net.minecraft.server.ServerListenThread.func_71766_a(ServerListenThread.java:55) at net.minecraft.server.dedicated.DedicatedServerListenThread.func_71747_b(SourceFile:29) at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:677) at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:275) at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:573) at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:470) at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:573) 2017-04-23 21:09:07 [INFO] ZacSlave[/73.147.41.111:61846] logged in with entity id 87 at (3434.300000011921, 69.5625, -1697.300000011921)