Can't find onClick method in action from xml definition

I am trying to bind a function to the onClick property of a button in AndroidStudio, but for some reason the system cannot identify the method I have coded.

The funny thing is that it works correctly when I code it in Java. This is not the case in Kotlin. I have updated my Kotlin and checked its configuration, but I cannot find the problem. A friend of mine tried the same thing on a Linux machine and it worked for him. I have a Mac OS, I don't know if there is any additional setup to take care of. Can anyone help me?

This is my simple activity:

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
    }

    fun sendMessage(view: View) {

    }
}

      

        
        
        
      

    

This is the xml:

<Button
    android:id="@+id/button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginEnd="16dp"
    android:layout_marginStart="16dp"
    android:layout_marginTop="16dp"
    android:onClick="sendMessage"
    android:text="@string/send_button"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toEndOf="@+id/editText"
    app:layout_constraintTop_toTopOf="parent" />

      

        
        
        
      

    

In build.gradle I have:

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

      

        
        
        
      

    

Error message:

Corresponding method handler 'public void sendMessage(android.view.View)' not found

The onClick attribute value should be the name of a method in this View context to invoke when the view is clicked.

This name must correspond to a public method that takes exactly one parameter of type View.  Must be a string value, using '\;' to escape characters such as '\n' or '\uxxxx' for a unicode character