title: fatal error: unexpectedly found nil while unwrapping an Optional value in UITableView
body: <p>While I am setting up a model for my chat screen info. I am getting the below error on this line</p>
  
  <pre><code>cell.chatViewLabel.text = chat.chatText
  </code></pre>
  
  <p><em>fatal error: unexpectedly found nil while unwrapping an Optional value</em></p>
  
  <p>Here is the code:</p>
  
  <pre><code>override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -&gt; UITableViewCell {
  
      // Table view cells are reused and should be dequeued using a cell identifier.
      let cellIdentifier = "ChatTableViewCell"
  
      guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as? ChatTableViewCell  else {
          fatalError("The dequeued cell is not an instance of ChatTableViewCell.")
      }
  
      // Fetches the appropriate chat for the data source layout.
      let chat = chats[indexPath.row]
      cell.chatViewLabel.text = chat.chatText
  
      return cell
  }
  </code></pre>
  
  <p>I am new in swift and any prompt help would be helpful. Thanks</p>