Obscure IDE Kotlin Error - Reference MusicPlayer programming exercise Kotlin

Question

https://code.sololearn.com/c2yu3I7n4Oej/?ref=app
Can you please help me with this error, it seems to be something to do with the IDE. ?

Answer 1

There are a lot of mistakes and you can compare them with your code

Answer 2

abstract class MusicPlayer(){
protected var arr = ArrayList<String>()
abstract fun show()
abstract fun add(name:String)
}

class ModelRx():MusicPlayer(){

override fun add(name :String){
arr.add(name)
}

override fun show(){
for (i in 0..arr.size-1) println (arr[i])
}
}

fun main(args: Array<String>) {
val m = ModelRx()

while(true) {
var input = readLine()!!
if(input == "stop") break
m.add(input)
}

m.show()
}

Answer 3

SoloProg Fantastic... but what was the error?