How to solve NSInvalidArgumentException error?
<p>My app is crashing intermittently for users, but unfortunately I am not able reproduce the problem on any of my devices.  The reported error is:</p>

<blockquote>
  <p>Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'NSConcreteAttributedString initWithString:: nil value'</p>
</blockquote>

<p>The log trace is not clear about the crash source.
I have attached a log trace.
I'm looking for any pointers that can help me to track this down.</p>

<p><a href="https://i.stack.imgur.com/tuARh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tuARh.png" alt="screenshot of sample exception"></a></p>