Command failed due to signal: Segmentation fault: 11 due to TableViewController? <p>In my 'DictionaryTableViewController: UITableViewController' class I define the below variables: </p> <pre><code>var dataObj : [String: AnyObject]! var letters : Int! var currentSection : Int!; var currentRow : Int! </code></pre> <p>In 'viewDidLoad' I have:</p> <pre><code> let jsonUrl = NSBundle.mainBundle().URLForResource("dictionary", withExtension: "json") var data = NSData(contentsOfURL: jsonUrl!) func dataReturn(object: [String: AnyObject]) { dataObj = object letters = object["collection"]!.count } do { let object = try NSJSONSerialization.JSONObjectWithData(data!, options: .AllowFragments) if let dictionary = object as? [String: AnyObject] { dataReturn(dictionary) } } catch { // Handle Error } </code></pre> <p>This is the basic structure of the JSON file that I am pulling in from NSBundle</p> <pre><code> { "collection": [{ "letter": "A", "words": [{ "word" : "Apple", "definition" : "Tasty fruit" }] },{ "letter": "B", "words": [{ "word" : "Banana", "definition" : "Meh, not bad." }] },{ "letter": "C", "words": [{ "word" : "Carrots", "definition" : "hooock twooo!" }] }] } </code></pre> <p>So now when I go style the tableView cell I believe that is what is causing this error:</p> <blockquote> <p>Command failed due to signal: Segmentation fault: 11</p> <ol> <li>While emitting SIL for 'tableView' at /Users/me/Desktop/.../DictionaryTableViewController.swift:70:14</li> </ol> </blockquote> <p>As a warning I am just getting this issue after updating to xcode 7.3. This issue was not present in 7.2 </p> <p>Line 70 from the where the error says to becoming from reads:</p> <pre><code>Line 70: override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -&gt; UITableViewCell { let cell = tableView.dequeueReusableCellWithIdentifier("reuseIdentifier", forIndexPath: indexPath) //let currentSelection = dataObj["collection"]![indexPath.section]["words"]!![indexPath.row]! let currentSelection = dataObj["collection"]![indexPath.section]["words"]!![indexPath.row]!!! cell.textLabel?.text = currentSelection["word"] as? String cell.detailTextLabel?.text = currentSelection["definition"] as? String return cell } </code></pre> <p>Note: The commented out line in the above code was working correctly in xcode 7.2. Xcode7.3 gave me a syntax error (Ambiguous use of subscript). The code just below the commented out line are my changes that produce no syntax errors. Is this what is causing my issue? I am really at a loss here and can't seem to find an answer. Any help is appreciated! </p>