Hello world!
Fatal error: Uncaught Error: Call to undefined function twentynineteen_post_thumbnail() in /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-content/themes/twentynineteen/template-parts/content/content.php:28 Stack trace: #0 /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-includes/template.php(812): require() #1 /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-includes/template.php(745): load_template('/home/users/0/a...', false, Array) #2 /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-includes/general-template.php(206): locate_template(Array, true, false, Array) #3 /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-content/themes/twentynineteen/index.php(29): get_template_part('template-parts/...') #4 /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-includes/template-loader.php(106): include('/home/users/0/a...') #5 /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-blog-header.php(19): require_once('/home/users/0/a...') #6 /home/users/0/akitawedding/web/akitawedding.jp/sys/index.php(17): require('/home/users/0/a...') #7 {main} thrown in /home/users/0/akitawedding/web/akitawedding.jp/sys/wp-content/themes/twentynineteen/template-parts/content/content.php on line 28