title: EF Lambda: The Include path expression must refer to a navigation property
body: <p>Here is my expression:</p>
  
  <pre><code>Course course = db.Courses
    .Include(
      i =&gt; i.Modules.Where(m =&gt; m.IsDeleted == false)
        .Select(s =&gt; s.Chapters.Where(c =&gt; c.IsDeleted == false))
    ).Include(i =&gt; i.Lab).Single(x =&gt; x.Id == id);
  </code></pre>
  
  <p>I know the cause is <code>Where(m =&gt; m.IsDeleted == false)</code> in the Modules portion, but why does it cause the error? More importantly, how do I fix it?</p>
  
  <p>If I remove the where clause it works fine but I want to filter out deleted modules.</p>