[21:23:51] [Server thread/ERROR]: Fatal error trying to convert Lobby-System v1.0:me/lobby/events/JoinEvent.class
org.bukkit.plugin.AuthorNagException: No legacy enum constant for PLAYER_HEAD. Did you forget to define api-version: 1.13 in your plugin.yml?
        at org.bukkit.craftbukkit.v1_14_R1.util.Commodore$1$1.visitFieldInsn(Commodore.java:176) ~[spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.libs.org.objectweb.asm.ClassReader.readCode(ClassReader.java:2210) ~[spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.libs.org.objectweb.asm.ClassReader.readMethod(ClassReader.java:1283) ~[spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.libs.org.objectweb.asm.ClassReader.accept(ClassReader.java:688) ~[spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.libs.org.objectweb.asm.ClassReader.accept(ClassReader.java:400) ~[spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.util.Commodore.convert(Commodore.java:130) ~[spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.util.CraftMagicNumbers.processClass(CraftMagicNumbers.java:283) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:108) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.plugin.java.JavaPluginLoader.getClassByName(JavaPluginLoader.java:202) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:92) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:81) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424) [?:1.8.0_222]
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357) [?:1.8.0_222]
        at me.lobby.Lobby.onEnable(Lobby.java:39) [LobbySystem.jar:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:263) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:352) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:417) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.CraftServer.enablePlugin(CraftServer.java:461) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.CraftServer.enablePlugins(CraftServer.java:375) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.CraftServer.reload(CraftServer.java:810) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.Bukkit.reload(Bukkit.java:576) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.command.defaults.ReloadCommand.execute(ReloadCommand.java:27) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:149) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.CraftServer.dispatchCommand(CraftServer.java:710) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at org.bukkit.craftbukkit.v1_14_R1.CraftServer.dispatchServerCommand(CraftServer.java:695) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.DedicatedServer.handleCommandQueue(DedicatedServer.java:433) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.DedicatedServer.b(DedicatedServer.java:397) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.MinecraftServer.a(MinecraftServer.java:971) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at net.minecraft.server.v1_14_R1.MinecraftServer.run(MinecraftServer.java:816) [spigot.jar:git-Spigot-9de398a-9c887d4]
        at java.lang.Thread.run(Thread.java:748) [?:1.8.0_222]