Thanks Shaon.
The url is: http://atesolutions.co.uk.gridhosted.co.uk/module-testing/flex-10/
On the right hand side there are a number of download links.
The first one is attempting to use the shortcode.
The next four are the original buttons with no shortcode.
The bottom button labelled ‘Download’ is using your shortcode but added via a text widget. This proves the shortcode works normally when not used in a custom field. However as I need different buttons on each page I cannot add them using the text widget.
I have added the following code to my page template used for that page:
echo apply_filters('the_content', get_post_meta($post->ID,'pdf_download_button', true));
The name of the custom field is: Pdf Download Button
Thanks for taking the time to help.
Kind Regards,
David