Error occurred while enabling MundoSK v1.8.5 (Is it up to date?)
java.lang.NoClassDefFoundError: org/bukkit/generator/ChunkGenerator$ChunkData
        at com.pie.tlatoani.Generator.GeneratorManager.load(GeneratorManager.java:22) ~[?:?]
        at com.pie.tlatoani.Registration.Registration.register(Registration.java:29) ~[?:?]
        at com.pie.tlatoani.Mundo.onEnable(Mundo.java:79) ~[?:?]
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321) ~[server.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:335) [server.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [server.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.craftbukkit.v1_8_R1.CraftServer.loadPlugin(CraftServer.java:356) [server.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.craftbukkit.v1_8_R1.CraftServer.enablePlugins(CraftServer.java:316) [server.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.q(MinecraftServer.java:402) [server.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.k(MinecraftServer.java:370) [server.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.a(MinecraftServer.java:325) [server.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.DedicatedServer.init(DedicatedServer.java:211) [server.jar:git-Spigot-c3c767f-33d5de3]
        at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:505) [server.jar:git-Spigot-c3c767f-33d5de3]
        at java.base/java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.ClassNotFoundException: org.bukkit.generator.ChunkGenerator$ChunkData
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:91) ~[server.jar:git-Spigot-c3c767f-33d5de3]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:86) ~[server.jar:git-Spigot-c3c767f-33d5de3]
        at java.base/java.lang.ClassLoader.loadClass(Unknown Source) ~[?:?]
        at java.base/java.lang.ClassLoader.loadClass(Unknown Source) ~[?:?]
        ... 14 more