title: Nullable object must have a value when deviding
body: <p>I have the following mapping:</p>
  <pre><code> .ForMember(dest =&gt; dest.AskerAverageRating, opt =&gt; opt.MapFrom(src =&gt;
        src.ReviewsReceived != null?
        ((float)src.ReviewsReceived.Sum(r =&gt; r.Rating) / (float)src.ReviewsReceived.Count()) : 0))  
  </code></pre>
  <p>This alone:</p>
  <pre><code>(float)src.ReviewsReceived.Sum(r =&gt; r.Rating)  
  </code></pre>
  <p>Works.</p>
  <p>This alone:</p>
  <pre><code>(float)src.ReviewsReceived.Count()  
  </code></pre>
  <p>Also works.</p>
  <p>Devided however, they give the following error:</p>
  <pre><code> System.InvalidOperationException: Nullable object must have a value.  
  </code></pre>
  <p>Why???</p>
  <p>Here are the relevant Properties and entities:</p>
  <p>This is the destination</p>
  <pre><code>public float AskerAverageRating { get; set; }  
  </code></pre>
  <p>These is the source:</p>
  <pre><code>public ICollection&lt;Review&gt; ReviewsReceived { get; set; }  
  </code></pre>
  <p>This is <code>Review</code>:</p>
  <pre><code>public class Review
  {
      ..
      public int Rating { get; set; }
      ..  
  </code></pre>
  <p>..And I found nothing funky in the DB.</p>