WKInterfaceTable & setNumberOfRows getting "unexpectedly found zero while expanding optional value" failure

I am working with WatchKit, I have a simple interface with only a table, but I am getting an error with only a few lines of code, maybe I forgot something really basic.

My interface:

the row inside the table has an id:

and a custom class:

The controller is implemented with this code:

import WatchKit
import Foundation

class ActiveListController: WKInterfaceController
{
    @IBOutlet weak var tableView: WKInterfaceTable!

    override func awakeWithContext(context: AnyObject?)
    {
        super.awakeWithContext(context)

        loadData()
    }

    override func willActivate()
    {
        // This method is called when watch view controller is about to be visible to user
        super.willActivate()
    }

    override func didDeactivate()
    {
        // This method is called when watch view controller is no longer visible
        super.didDeactivate()
    }

    func loadData()
    {
        tableView.setNumberOfRows(10, withRowType: "ItemRow") // GET ERROR

        for index in 0...9
        {
            let row = tableView.rowControllerAtIndex(index) as! ItemRow

            row.nameLabel.setText("test")
        }
    }

}

      

        
        
        
      

    

and obviously I have my own custom class for one line

import Foundation
import WatchKit

class ItemRow : NSObject
{
    @IBOutlet weak var checkImage: WKInterfaceImage!
    @IBOutlet weak var nameLabel: WKInterfaceLabel!
}

      

        
        
        
      

    

So when I run the application, I get an error when I try to set the number of lines, but I really can't figure out what nil is:

fatal error: unexpectedly found nil while expanding an optional value

Maybe this is a simple error, maybe not, but please help me: \