title: how to fix EXC_BAD_INSTRUCTION(code=EXC_1386_INVOP, subcode=0x0) in swift
body: <p>Am making image library that make me abel to select multiple image from the collection view that i made
  When i fun my code averting is good ,but when i press select button this error happen "EXC_BAD_INSTRUCTION(code=EXC_1386_INVOP, subcode=0x0)"</p>
  
  <p>this is the select button code</p>
  
  <pre><code>@IBAction func Select(sender: AnyObject) {
      var ckeck = AssetCell() as? AssetCell
      ckeck!.CheckMarkView1.hidden = false // here it shows an error which is "Thread 1:EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0)"
                                           }
  </code></pre>
  
  <p>i had Assetcell class that contain CheckMarkView1</p>