Hi @nosilver4u,
I have the same problem. I set my dev env to show all errors with symfony debug mode, and when I updated to 2.5.1, I got this error all over my wp-admin.
The problem is indeed triggered by core code, but its origin is common.php, unregister_setting() function.
Hope this helps to release a patch.
ContextErrorException in plugin.php line 1837:
Notice: Undefined index: ewww_image_optimizer_options
in plugin.php line 1837
at ErrorHandler->handleError(‘8’, ‘Undefined index: ewww_image_optimizer_options’, ‘/srv/www/site/wp/wp-admin/includes/plugin.php’, ‘1837’, array(‘option_group’ => ‘ewww_image_optimizer_options’, ‘option_name’ => ‘ewww_image_optimizer_cloud_key’, ‘sanitize_callback’ => ”, ‘new_whitelist_options’ => array(‘wpuxss_eml_taxonomies’ => array(‘wpuxss_eml_taxonomies’, ‘wpuxss_eml_tax_options’), ‘wpuxss_eml_mimes’ => array(‘wpuxss_eml_mimes’), ‘wpuxss_eml_mimes_backup’ => array(‘wpuxss_eml_mimes_backup’)))) in plugin.php line 1837
at unregister_setting(‘ewww_image_optimizer_options’, ‘ewww_image_optimizer_cloud_key’) in common.php line 702
at ewww_image_optimizer_install_table() in common.php line 438
at ewww_image_optimizer_init() in common.php line 451
at ewww_image_optimizer_admin_init(”)
at call_user_func_array(‘ewww_image_optimizer_admin_init’, array(”)) in plugin.php line 503
at do_action(‘admin_init’) in admin.php line 168
at require_once(‘/srv/www/site/wp/wp-admin/admin.php’) in index.php line 10