Can't run nukkit

[tylergraf]

When I try to run a local nukkit server I get this error:

07:04:15 [WARN ] Level "nether" not found
07:04:15 [INFO ] No level called "nether" found, creating default nether level.
07:04:15 [INFO ] Preparing level "nether"
07:04:15 [INFO ] Enabling BossBarAPI v1.0.0
07:04:15 [INFO ] Enabling MultiWorld v1.0
07:04:15 [INFO ] [Pokkit] [scriptcraft] Enabling scriptcraft v3.4.0-2019-01-20
[0] > javax.script.ScriptException: org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined
[0] 	at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:350)
[0] 	at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:312)
[0] 	at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:249)
[0] 	at org.scriptcraftjs.bukkit.ScriptCraftPlugin.onEnable(ScriptCraftPlugin.java:36)
[0] 	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:264)
[0] 	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:339)
[0] 	at nl.rutgerkok.pokkit.plugin.PokkitPluginLoader.enablePlugin(PokkitPluginLoader.java:69)
[0] 	at cn.nukkit.plugin.PluginManager.enablePlugin(PluginManager.java:439)
[0] 	at cn.nukkit.Server.enablePlugin(Server.java:733)
[0] 	at cn.nukkit.Server.enablePlugins(Server.java:722)
[0] 	at cn.nukkit.Server.<init>(Server.java:558)
[0] 	at cn.nukkit.Nukkit.main(Nukkit.java:112)
[0] Caused by: org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined
[0] 	at <js>.:anonymous(<eval>:6)
[0] 	at <js>.:program(<eval>:5)
[0] 	at org.graalvm.polyglot.Context.eval(Context.java:344)
[0] 	at com.oracle.truffle.js.scriptengine.GraalJSScriptEngine.eval(GraalJSScriptEngine.java:348)
[0] 	... 11 more
07:04:15 [ERROR] [Pokkit] [scriptcraft] org.graalvm.polyglot.PolyglotException: ReferenceError: java is not defined

Any idea why? It seems like I could create a nether level somehow, I just don't know how.