fb:multi-friend-selector throws ERROR

Question

Hi,

i think something is wrong with my friend-selector. I can select friends an open the invite-dialog. But as soos as i try to send the invition I get: Sorry, your request could not be processed.

That happens even I use the code from the docs

Code:

<div style="padding: 10px;">
  <fb:request-form method="post" ncontent="hey" type="sample" invite="true">
    <div class="clearfix" style="padding-bottom: 10px;">
      <fb:multi-friend-selector condensed="true" selected_rows="0" style="width: 200px;" />
    </div>
    <fb:request-form-submit />
  </fb:request-form>
</div>

Thanks for helping.