fatal error

I am receiving fatal errors as I am uploading listings and my members are as well.
After clicking save listing. We receive the error. then in the listing page the listing shows but without images.

Fatal error: Cannot use object of type WP_Error as array in /home/content/p3pnexwpnas16_data01/33/3766433/html/wp-content/themes/DL/tpl-add.php on line 577

Hello Matt,
Please disable all your plugins first.If still not working please open a ticket >>http://s.premiumpress.com/index.php?/Tickets/Submit