Disable WYSIWYG in CRED form

I've seen a few previous questions regarding disabling the WYSIWYG editor on the front end of a CRED form for the cred-field-post_content but none of the solutions seem to work for me.

http://wp-types.com/forums/topic/disable-wysiwyg-on-front-end-cred-form/
http://wp-types.com/forums/topic/turn-of-wysiwyg-in-post_content/
http://wp-types.com/forums/topic/cred-remove-wysiwyg-on-the-content-field/

Wordpress Ver 3.9.1

CRED Version 1.3b3
Types Version 1.6b3
Views Version 1.6.1

My Theme is BusiProf Pro Ver 1.4

– I've turned of 'editor' in the CPT.
– I created an alternate field 'post_content_substitute' and updated functions.php with the suggested code:

function my_save_content($post_id)
{
$content=$_POST['post_content_substitute'];
wp_update_post(
array(
'ID'=>$post_id,
'post_content'=>$content
)
);
}

which gave me an error across the top of the site. (so I remove the code because the site is live).

Regards,

Larry