file_get_contents failure

I am getting this message if I try to log in to administer my WP site, or if I try to go to the website itself:

Warning: file_get_contents(/myhostsite/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/nextgen_xmlrpc/module.nextgen_xmlrpc.php): failed to open stream: Permission denied in /myhostsite/public_html/wp-content/plugins/nextgen-gallery/pope/lib/class.component_registry.php on line 788
/myhostsite/public_html/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/nextgen_xmlrpc/module.nextgen_xmlrpc.php is not a valid Pope module

I have no clue where to look or to start to repair this on myhostsite. What am I looking for / what should I do?