'EntityState' is an ambiguous reference between 'System.Data.EntityState' and 'System.Data.Entity.EntityState'
<p>I'm getting the error </p>

<blockquote>
  <p>'EntityState' is an ambiguous reference between
  'System.Data.EntityState' and 'System.Data.Entity.EntityState'</p>
</blockquote>

<p>I'm getting this error on my 4 controllers using <strong>mvc5 entity framework</strong>.</p>

<p>The line in question is <code>db.Entry(director).State = EntityState.Modified;</code></p>

<p>Same on each controller just different models. </p>