Any page of the forum with several posts can't be validate, because each post adds own ID.
Error: Duplicate ID Id.
<input data-val="true" data-val-number="The field Id must be a number." id="Id" name="Id" type="hidden"
Wrong code
<div class="post-text">
@Html.Raw(Model.FormattedText)
@Html.Hidden("Id", Model.Id)
</div>
Good code
<div class="post-text">
@Html.Raw(Model.FormattedText)
</div>