title: An error occurred while updating the entries. For more information, see inner exception
body: <p>I am using Entity Framework to populate a grid control. It sometimes when I make updates I get the following error:</p>
  
  <blockquote>
    <p>An error occurred while updating the entries. For more information, see inner exception.</p>
  </blockquote>
  
  <p>This my action Edit : </p>
  
  <pre><code>public ActionResult Edit(CollaborateurSet collaborateur)
  {
      if (ModelState.IsValid)
      {
          _db.Entry(collaborateur).State = EntityState.Modified;
          _db.SaveChanges();
      }
      else
      {
          DilpomeDropDownList(collaborateur.Diplome_idDiplome);
          return View(collaborateur);
      }
  }
  </code></pre>
  
  <p>And this is the view edit :</p>
  
  <pre><code>@using (Html.BeginForm()) 
  {
      @Html.HiddenFor(model =&gt; model.idCollaborateur)
  
      &lt;div class="editor-label"&gt;
          @Html.LabelFor(model =&gt; model.nom)
      &lt;/div&gt;
      &lt;div class="editor-field"&gt;
          @Html.EditorFor(model =&gt; model.nom)
          @Html.ValidationMessageFor(model =&gt; model.nom)
      &lt;/div&gt;
  </code></pre>
  
  <p>Please tell me how can I resolve this error </p>