Error

[18:49:39 ERROR]: Could not load 'plugins\Yok-Kingdom.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.Error: Unresolved compilation problems:
        The type List is not generic; it cannot be parameterized with arguments <String>
        wereldlist cannot be resolved or is not a field
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        wereldlist cannot be resolved or is not a field
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>

        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:329) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugins(CraftServer.java:292) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:198) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:525) [spigot.jar:git-Spigot-db6de12-18fbb24]
        at java.base/java.lang.Thread.run(Unknown Source) [?:?]
Caused by: java.lang.Error: Unresolved compilation problems:
        The type List is not generic; it cannot be parameterized with arguments <String>
        wereldlist cannot be resolved or is not a field
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        wereldlist cannot be resolved or is not a field
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>
        The type List is not generic; it cannot be parameterized with arguments <String>

        at me.iclicks.yok.main.Kingdom.<init>(Kingdom.java:28) ~[?:?]
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:?]
        at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[?:?]
        at java.base/java.lang.reflect.Constructor.newInstance(Unknown Source) ~[?:?]
        at java.base/java.lang.Class.newInstance(Unknown Source) ~[?:?]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:76) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:131) ~[spigot.jar:git-Spigot-db6de12-18fbb24]
        ... 6 more