[Bug Report] Show a relevant error message when trying to use eval with an invalid script enging

[ramboozer]

Bug Description

Eval not working
Version 0.4.0

Steps to Reproduce

DM or in channel
.eval jda.guilds

Expected Result

I expect it to list the servers it in currently in.

Debug Output

`System Properties:
java.version = 20.0.1
java.vm.name = Java HotSpot(TM) 64-Bit Server VM
java.vm.specification.version = 20
java.runtime.name = Java(TM) SE Runtime Environment
java.runtime.version = 20.0.1+9-29
java.specification.version = 20
os.arch = amd64
os.name = Windows 10

JMusicBot Information:
Version = 0.4.0
Owner =
Prefix = .
AltPrefix = null
MaxSeconds = 0
NPImages = false
SongInStatus = true
StayInChannel = true
UseEval = true
UpdateAlerts = true

Dependency Information:
JDA Version = 4.4.1_353
JDA-Utilities Version = 3.0.5
Lavaplayer Version = 727959e9f621fc457b3a5adafcfffb55fdeaa538-SNAPSHOT

Runtime Information:
Total Memory = 40
Used Memory = 23

Discord Information:
ID =
Guilds = 3
Users = 18`

Additional Info

[16:40:19] [ERROR] [JDA]: One of the EventListeners had an uncaught exception
java.lang.NullPointerException: Cannot invoke "javax.script.ScriptEngine.put(String, Object)" because "se" is null
at com.jagrosh.jmusicbot.commands.owner.EvalCmd.execute(EvalCmd.java:46)
at com.jagrosh.jdautilities.command.Command.run(Command.java:323)
at com.jagrosh.jdautilities.command.impl.CommandClientImpl.onMessageReceived(CommandClientImpl.java:557)
at com.jagrosh.jdautilities.command.impl.CommandClientImpl.onEvent(CommandClientImpl.java:445)
at net.dv8tion.jda.api.hooks.InterfacedEventManager.handle(InterfacedEventManager.java:96)
at net.dv8tion.jda.internal.hooks.EventManagerProxy.handleInternally(EventManagerProxy.java:88)
at net.dv8tion.jda.internal.hooks.EventManagerProxy.handle(EventManagerProxy.java:70)
at net.dv8tion.jda.internal.JDAImpl.handleEvent(JDAImpl.java:160)
at net.dv8tion.jda.internal.handle.MessageCreateHandler.handleInternally(MessageCreateHandler.java:123)
at net.dv8tion.jda.internal.handle.SocketHandler.handle(SocketHandler.java:36)
at net.dv8tion.jda.internal.requests.WebSocketClient.onDispatch(WebSocketClient.java:952)
at net.dv8tion.jda.internal.requests.WebSocketClient.onEvent(WebSocketClient.java:839)
at net.dv8tion.jda.internal.requests.WebSocketClient.handleEvent(WebSocketClient.java:817)
at net.dv8tion.jda.internal.requests.WebSocketClient.onBinaryMessage(WebSocketClient.java:991)
at com.neovisionaries.ws.client.ListenerManager.callOnBinaryMessage(ListenerManager.java:385)
at com.neovisionaries.ws.client.ReadingThread.callOnBinaryMessage(ReadingThread.java:276)
at com.neovisionaries.ws.client.ReadingThread.handleBinaryFrame(ReadingThread.java:996)
at com.neovisionaries.ws.client.ReadingThread.handleFrame(ReadingThread.java:755)
at com.neovisionaries.ws.client.ReadingThread.main(ReadingThread.java:108)
at com.neovisionaries.ws.client.ReadingThread.runMain(ReadingThread.java:64)
at com.neovisionaries.ws.client.WebSocketThread.run(WebSocketThread.java:45)

Checklist

• I have looked for information about this within the documentation
• I have searched for similar issues on the issues page
• I am running the latest version of the bot:

[jagrosh]

This is because you're running java version 20, and the script engine we use was removed by that version. Try installing an older version (ideally 11).

[jagrosh]

Renaming this because a stopgap solution for this is to print an error when attempting to run the eval command instead of only printing a stacktrace to the console.