東京タワーに向かって打て！

Fatal error: Uncaught Error: Call to undefined function get_field() in /home/wingfield/wingfield.gr.jp/public_html/wp/wp-content/plugins/wingfield-custom-plugin/functions_attachment_file.php:10 Stack trace: #0 /home/wingfield/wingfield.gr.jp/public_html/wp/wp-includes/class-wp-hook.php(324): add_custom_content_after_post_body('<p>\xE3\x81\xA8\xE3\x81\x84\xE3\x81\x86\xE3\x81\x93...') #1 /home/wingfield/wingfield.gr.jp/public_html/wp/wp-includes/plugin.php(205): WP_Hook->apply_filters('<p>\xE3\x81\xA8\xE3\x81\x84\xE3\x81\x86\xE3\x81\x93...', Array) #2 /home/wingfield/wingfield.gr.jp/public_html/wp/wp-includes/post-template.php(256): apply_filters('the_content', '\xE3\x81\xA8\xE3\x81\x84\xE3\x81\x86\xE3\x81\x93\xE3\x81\xA8...') #3 /home/wingfield/wingfield.gr.jp/public_html/wp/wp-content/themes/swell/single.php(39): the_content() #4 /home/wingfield/wingfield.gr.jp/public_html/wp/wp-includes/template-loader.php(106): include('/home/wingfield...') #5 /home/wingfield/wingfield.gr.jp/public_html/wp/wp-blog-header.php(19): require_once('/home/wingfield...') #6 /home/wingfield/wingfield.gr.jp/public_html/index.php(7): require('/home/wingfield...') #7 {main} thrown in /home/wingfield/wingfield.gr.jp/public_html/wp/wp-content/plugins/wingfield-custom-plugin/functions_attachment_file.php on line 10