crash tab

[15:57:45] [Client thread/FATAL]: Unreported exception thrown!
java.lang.NullPointerException
	at net.minecraft.client.gui.GuiNewChat.func_146242_c(GuiNewChat.java:388) ~[bcc.class:?]
	at net.minecraft.client.gui.GuiNewChat.func_146237_a(GuiNewChat.java:161) ~[bcc.class:?]
	at net.minecraft.client.gui.GuiNewChat.func_146234_a(GuiNewChat.java:148) ~[bcc.class:?]
	at net.minecraft.client.gui.GuiChat.func_146404_p_(GuiChat.java:331) ~[bct.class:?]
	at net.minecraft.client.gui.GuiChat.func_146406_a(GuiChat.java:491) ~[bct.class:?]
	at net.minecraft.client.network.NetHandlerPlayClient.func_147274_a(NetHandlerPlayClient.java:1405) ~[bjb.class:?]
	at net.minecraft.network.play.server.S3APacketTabComplete.func_148833_a(SourceFile:41) ~[gi.class:?]
	at net.minecraft.network.play.server.S3APacketTabComplete.func_148833_a(SourceFile:10) ~[gi.class:?]
	at net.minecraft.network.NetworkManager.func_74428_b(NetworkManager.java:212) ~[ej.class:?]
	at net.minecraft.client.multiplayer.PlayerControllerMP.func_78765_e(PlayerControllerMP.java:273) ~[bje.class:?]
	at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1601) ~[bao.class:?]
	at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:972) ~[bao.class:?]
	at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:898) [bao.class:?]
	at net.minecraft.client.main.Main.main(SourceFile:148) [Main.class:?]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_191]
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_191]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_191]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_191]
	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:?]