【解決方法】Waiting for cache lock: Could not get lock /var/lib/dpkg/lock-frontend.【いつものエラー】


Fatal error: Uncaught Error: Call to undefined function MarkupMarkdown\Core\wp_is_rest_endpoint() in /home/web13c/bistro.site/public_html/wp-content/plugins/markup-markdown/MarkupMarkdown/Core/Support.php:304 Stack trace: #0 /home/web13c/bistro.site/public_html/wp-content/plugins/markup-markdown/MarkupMarkdown/Core/Support.php(327): MarkupMarkdown\Core\Support->content_data('<h2>\xE5\x8D\xB3\xE8\xA7\xA3\xE6\xB1\xBA\xE6\xB3...', 1) #1 /home/web13c/bistro.site/public_html/wp-includes/class-wp-hook.php(324): MarkupMarkdown\Core\Support->post_content_mmd2html('<h2>\xE5\x8D\xB3\xE8\xA7\xA3\xE6\xB1\xBA\xE6\xB3...') #2 /home/web13c/bistro.site/public_html/wp-includes/plugin.php(205): WP_Hook->apply_filters('<h2>\xE5\x8D\xB3\xE8\xA7\xA3\xE6\xB1\xBA\xE6\xB3...', Array) #3 /home/web13c/bistro.site/public_html/wp-content/themes/luxeritas/inc/filters.php(292): apply_filters('the_content', '<h2>\xE5\x8D\xB3\xE8\xA7\xA3\xE6\xB1\xBA\xE6\xB3...') #4 /home/web13c/bistro.site/public_html/wp-includes/class-wp-hook.php(324): {closure}('<h2>\ in /home/web13c/bistro.site/public_html/wp-content/plugins/markup-markdown/MarkupMarkdown/Core/Support.php on line 304