If you’re getting an XML error when you’re using Facebook Connect to post to a users stream using the function:

$facebook->render_prompt_feed_url()

Then ensure the following:

  • You don’t have any double quotes in your attachment
  • You don’t have any ampersands in your return URL

For some reason the content is being placed in a hidden field on the page on “mobile” devices.  This isn’t escaping the contents of the post, and hence breaks if you have any of the above.

Highly frustrating!  Hope this helps someone.