Fatal error

[error] 21256#21256: *20929 FastCGI sent in stderr: “PHP message: PHP Notice: Trying to get property ‘use_trailing_slashes’ of non-object in /wp-includes/link-template.php on line 49
PHP message: PHP Notice: Trying to get property ‘use_trailing_slashes’ of non-object in /wp-includes/link-template.php on line 49
PHP message: PHP Notice: Trying to get property ‘use_trailing_slashes’ of non-object in /wp-includes/link-template.php on line 49
PHP message: PHP Fatal error: Uncaught Error: Call to a member function get_page_permastruct() on null in /wp-includes/link-template.php:373
Stack trace:
#0 /wp-includes/link-template.php(335): _get_page_link(Object(WP_Post), false, false)
#1 /wp-includes/link-template.php(146): get_page_link(Object(WP_Post), false, false)
#2 /wp-content/plugins/wp-seo-plugin-optimizer/functions.php(466): get_permalink(Object(WP_Post))
#3 /wp-content/plugins/wp-seo-plugin-optimizer/functions.php(444): wspo_update_page_register_post(33088)
#4 /wp-content/plugins/wp-seo-plugin-optimizer/functions.php(640): {closure}(33088)
#5 /wp-content/plugins/wp-seo-plugin-optimizer/functions.php(445): wspo_batch_page_loop(‘page’, Object(Closure))
#6 /wp-content/plugins/wp-seo-plugin-optimizer/wspo.php(144): wspo_update_page_register()
#7 /wp-content/plugins/w” while reading response header from upstream, client: 95.255.259.160, …..