When I try to hide my background image using a UISwitch in a different storyboard, It doesn't work. Swift 4 : <p>When I turn on the UISwitch I try to make it hide the background Image but I get the error: Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value.
What am I doing wrong? when it was on the main storyboard it worked fine, but when on the settings storyboard it doesn't.</p>

<p>Code:</p>

<pre><code>@IBAction func switchBackground(_ sender: UISwitch) {

    if (sender.isOn == true) {
    Background!.isHidden = false
    amountDue.textColor = UIColor.white
    amountMoney.textColor = UIColor.white
    amountPeople.textColor = UIColor.white
    }else {
    Background!.isHidden = true
    amountDue.textColor = UIColor.black
    amountMoney.textColor = UIColor.black
    amountPeople.textColor = UIColor.black
    amountDueText.textColor = UIColor.black
    amountPeopleText.textColor = UIColor.black
    amountMoneyText.textColor = UIColor.black

    }

}
</code></pre>
