As the title says,when I typed ".b follow entity sheep" or ".b follow entity chicken" or everything else, it didn't work and asked me to report it on Github.So I'm here.The details in game log are here:
[23:28:17] [Client thread/INFO] [net.minecraft.client.gui.GuiNewChat]: [CHAT] [Baritone] > follow entity donkey
[23:28:17] [Client thread/INFO] [net.minecraft.client.gui.GuiNewChat]: [CHAT] [Baritone] An unhandled exception occurred. The error is in your game's log, please report this at https://github.com/cabaletta/baritone/issues
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: baritone.api.command.exception.CommandUnhandledException: java.lang.NoSuchFieldError: field_191308_b
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at baritone.cd.execute(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at baritone.x.a(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at baritone.x.onSendChatMessage(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at baritone.cf.a(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at java.util.concurrent.CopyOnWriteArrayList.forEach(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at baritone.cf.onSendChatMessage(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at inertia.EHBm.eAdv(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at inertia.jphK.awJh(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at inertia.QTto.JbBq(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.entity.EntityPlayerSP.handler$rpDE$zck000(EntityPlayerSP.java:1900)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.entity.EntityPlayerSP.func_71165_d(EntityPlayerSP.java)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.gui.GuiScreen.func_175281_b(GuiScreen.java:424)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.gui.GuiScreen.func_175275_f(GuiScreen.java:411)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.gui.GuiChat.func_73869_a(SourceFile:81)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.gui.GuiScreen.func_146282_l(GuiScreen.java:558)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.gui.GuiScreen.func_146269_k(GuiScreen.java:512)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.Minecraft.func_71407_l(Minecraft.java:1759)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.Minecraft.func_71411_J(Minecraft.java:1098)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:398)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.client.main.Main.main(SourceFile:123)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at java.lang.reflect.Method.invoke(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
[23:28:17] [Client thread/INFO] [STDERR]: [baritone.api.command.exception.CommandUnhandledException:handle:-1]: at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
[23:28:17] [Client thread/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: Caused by: java.lang.NoSuchFieldError: field_191308_b
[23:28:17] [Client thread/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at baritone.api.command.datatypes.EntityClassById.get(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at baritone.api.command.datatypes.EntityClassById.get(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at baritone.ag.getDatatypeFor(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: at baritone.bb.execute(Unknown Source)
[23:28:17] [Client thread/INFO] [STDERR]: [java.lang.Throwable:printStackTrace:-1]: ... 26 more

btw I don't know how to add a tag.excuse me.

This is a duplicate. Please search before creating an issue next time.