Causes: If you changed the WordPress table prefix or you are using woocommerce you can faced with the Sorry, you are not allowed to access this page problem.
Solution 1 and 2 for who changed the table prefix in database
Solution 1 – phpMyadmin > SQL run the query below.
SELECT * FROM `wp_options` WHERE `option_name` LIKE '%wp_%'
You can change wp_options with your table prefix.
Simply rename all of them to the new prefix.
Solution 2 –
SELECT * FROM `wp_usermeta` WHERE `meta_key` LIKE ‘%wp_%’
You can change wp_usermeta with your table prefix.
Simply rename all of them to the new prefix.
Solution 3 – Go to phpMyadmin > wp_options > Insert
option_name : wp_user_roles
option_value : a:5:{s:13:"administrator";a:2:{s:4:"name";s:13:"Administrator";s:12:"capabilities";a:61:{s:13:"switch_themes";b:1;s:11:"edit_themes";b:1;s:16:"activate_plugins";b:1;s:12:"edit_plugins";b:1;s:10:"edit_users";b:1;s:10:"edit_files";b:1;s:14:"manage_options";b:1;s:17:"moderate_comments";b:1;s:17:"manage_categories";b:1;s:12:"manage_links";b:1;s:12:"upload_files";b:1;s:6:"import";b:1;s:15:"unfiltered_html";b:1;s:10:"edit_posts";b:1;s:17:"edit_others_posts";b:1;s:20:"edit_published_posts";b:1;s:13:"publish_posts";b:1;s:10:"edit_pages";b:1;s:4:"read";b:1;s:8:"level_10";b:1;s:7:"level_9";b:1;s:7:"level_8";b:1;s:7:"level_7";b:1;s:7:"level_6";b:1;s:7:"level_5";b:1;s:7:"level_4";b:1;s:7:"level_3";b:1;s:7:"level_2";b:1;s:7:"level_1";b:1;s:7:"level_0";b:1;s:17:"edit_others_pages";b:1;s:20:"edit_published_pages";b:1;s:13:"publish_pages";b:1;s:12:"delete_pages";b:1;s:19:"delete_others_pages";b:1;s:22:"delete_published_pages";b:1;s:12:"delete_posts";b:1;s:19:"delete_others_posts";b:1;s:22:"delete_published_posts";b:1;s:20:"delete_private_posts";b:1;s:18:"edit_private_posts";b:1;s:18:"read_private_posts";b:1;s:20:"delete_private_pages";b:1;s:18:"edit_private_pages";b:1;s:18:"read_private_pages";b:1;s:12:"delete_users";b:1;s:12:"create_users";b:1;s:17:"unfiltered_upload";b:1;s:14:"edit_dashboard";b:1;s:14:"update_plugins";b:1;s:14:"delete_plugins";b:1;s:15:"install_plugins";b:1;s:13:"update_themes";b:1;s:14:"install_themes";b:1;s:11:"update_core";b:1;s:10:"list_users";b:1;s:12:"remove_users";b:1;s:13:"promote_users";b:1;s:18:"edit_theme_options";b:1;s:13:"delete_themes";b:1;s:6:"export";b:1;}}s:6:"editor";a:2:{s:4:"name";s:6:"Editor";s:12:"capabilities";a:34:{s:17:"moderate_comments";b:1;s:17:"manage_categories";b:1;s:12:"manage_links";b:1;s:12:"upload_files";b:1;s:15:"unfiltered_html";b:1;s:10:"edit_posts";b:1;s:17:"edit_others_posts";b:1;s:20:"edit_published_posts";b:1;s:13:"publish_posts";b:1;s:10:"edit_pages";b:1;s:4:"read";b:1;s:7:"level_7";b:1;s:7:"level_6";b:1;s:7:"level_5";b:1;s:7:"level_4";b:1;s:7:"level_3";b:1;s:7:"level_2";b:1;s:7:"level_1";b:1;s:7:"level_0";b:1;s:17:"edit_others_pages";b:1;s:20:"edit_published_pages";b:1;s:13:"publish_pages";b:1;s:12:"delete_pages";b:1;s:19:"delete_others_pages";b:1;s:22:"delete_published_pages";b:1;s:12:"delete_posts";b:1;s:19:"delete_others_posts";b:1;s:22:"delete_published_posts";b:1;s:20:"delete_private_posts";b:1;s:18:"edit_private_posts";b:1;s:18:"read_private_posts";b:1;s:20:"delete_private_pages";b:1;s:18:"edit_private_pages";b:1;s:18:"read_private_pages";b:1;}}s:6:"author";a:2:{s:4:"name";s:6:"Author";s:12:"capabilities";a:10:{s:12:"upload_files";b:1;s:10:"edit_posts";b:1;s:20:"edit_published_posts";b:1;s:13:"publish_posts";b:1;s:4:"read";b:1;s:7:"level_2";b:1;s:7:"level_1";b:1;s:7:"level_0";b:1;s:12:"delete_posts";b:1;s:22:"delete_published_posts";b:1;}}s:11:"contributor";a:2:{s:4:"name";s:11:"Contributor";s:12:"capabilities";a:5:{s:10:"edit_posts";b:1;s:4:"read";b:1;s:7:"level_1";b:1;s:7:"level_0";b:1;s:12:"delete_posts";b:1;}}s:10:"subscriber";a:2:{s:4:"name";s:10:"Subscriber";s:12:"capabilities";a:2:{s:4:"read";b:1;s:7:"level_0";b:1;}}}