Plugin conflict with Theme

I have installed a plugin called WP User Frontend. I was told this is the best plugin to allow posts to be created on the frontend. I am using this with a Plugin called Ultimate Member. The Plugin Developer has narrowed down we have a conflict with the theme. When you are logged in as a user it allows you to add a post. When you click on this button it brings up a page with an old shortcode [wpuf_addpost]. The plugin developer said they discontinued this with the update that I did install. I created a new form shortcode and added it to the page http://www.mylivinghhistory.org/add-post. When I try adding a post I get this error – Catchable fatal error: Object of class WP_Error could not be converted to string in /home/history/public_html/wp-content/themes/HighendWP/functions/breadcrumbs.php on line 96

The page I was trying to add the post on and has the old shortcode is http://www.mylivinghistory.org/user/randy.kasssebaum