weird exception during joining server

11:49:52] [main/INFO] [grimpack]: {Grim Pack}: Syncing config from server...
[11:49:52] [main/INFO] [grimpack]: {Grim Pack}: Updating manual pages...
[11:49:52] [main/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_152]
	at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_152]
	at net.minecraft.util.Util.func_181617_a(SourceFile:47) [h.class:?]
	at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1086) [bib.class:?]
	at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:397) [bib.class:?]
	at net.minecraft.client.main.Main.main(SourceFile:123) [Main.class:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_152]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_152]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_152]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_152]
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?]
	at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
Caused by: java.lang.NullPointerException
	at DummyCore.Utils.MiscUtils.getPlayerFromUsername(MiscUtils.java:1044) ~[MiscUtils.class:?]
	at DummyCore.Utils.MiscUtils.getPlayerFromUUID(MiscUtils.java:1048) ~[MiscUtils.class:?]
	at essentialcraft.network.ECPacketDispatcher.handleMessage(ECPacketDispatcher.java:38) ~[ECPacketDispatcher.class:?]
	at essentialcraft.network.ECPacketDispatcher.lambda$onMessage$0(ECPacketDispatcher.java:30) ~[ECPacketDispatcher.class:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_152]
	at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_152]
	at net.minecraft.util.Util.func_181617_a(SourceFile:46) ~[h.class:?]
	... 9 more
[11:49:52] [main/FATAL]: Error executing task
java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(Unknown Source) ~[?:1.8.0_152]
	at java.util.concurrent.FutureTask.get(Unknown Source) ~[?:1.8.0_152]
	at net.minecraft.util.Util.func_181617_a(SourceFile:47) [h.class:?]
	at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1086) [bib.class:?]
	at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:397) [bib.class:?]
	at net.minecraft.client.main.Main.main(SourceFile:123) [Main.class:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_152]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_152]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_152]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_152]
	at net.minecraft.launchwrapper.Launch.launch(Launch.java:135) [launchwrapper-1.12.jar:?]
	at net.minecraft.launchwrapper.Launch.main(Launch.java:28) [launchwrapper-1.12.jar:?]
Caused by: java.lang.NullPointerException
	at DummyCore.Utils.MiscUtils.getPlayerFromUsername(MiscUtils.java:1044) ~[MiscUtils.class:?]
	at DummyCore.Utils.MiscUtils.getPlayerFromUUID(MiscUtils.java:1048) ~[MiscUtils.class:?]
	at essentialcraft.network.ECPacketDispatcher.handleMessage(ECPacketDispatcher.java:38) ~[ECPacketDispatcher.class:?]
	at essentialcraft.network.ECPacketDispatcher.lambda$onMessage$0(ECPacketDispatcher.java:30) ~[ECPacketDispatcher.class:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_152]
	at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_152]
	at net.minecraft.util.Util.func_181617_a(SourceFile:46) ~[h.class:?]
	... 9 more