Please follow these steps to solve this problem.
1. find the functions.php file in your "vantage" root folder.
2. edit it and add the line "require( dirname( __FILE__ ) . '/includes/capabilities.php' );" after the line "require( dirname( __FILE__ ) . '/includes/core.php' );"
3. open your browser and add the "/
wp-admin/admin.php?page=app-settings&firstrun=1" to the end of your url.
example :
Your url:
http://www.example.com
add the "/
wp-admin/admin.php?page=app-settings&firstrun=1" to the end like
http://www.example.com/wp-admin/admin.php?page=app-settings&firstrun=1
and hit enter.
After these changes you should be ready to create listings.
Please let me know if you need further assistance. The beta will be updated to include this "fix".