JavaOne 2017 虽然已经落幕，但学习远未结束

Fatal error: Uncaught Error: Call to undefined function B2\Modules\Common\mb_convert_encoding() in /www/wwwroot/kuajing.club/wp-content/themes/b2/Modules/Common/Post.php:91 Stack trace: #0 /www/wwwroot/kuajing.club/wp-content/themes/b2/Modules/Common/Post.php(150): B2\Modules\Common\Post::b2_lazyload_action() #1 /www/wwwroot/kuajing.club/wp-includes/class-wp-hook.php(324): B2\Modules\Common\Post->b2_lazyload() #2 /www/wwwroot/kuajing.club/wp-includes/plugin.php(205): WP_Hook->apply_filters() #3 /www/wwwroot/kuajing.club/wp-includes/post-template.php(256): apply_filters() #4 /www/wwwroot/kuajing.club/wp-content/themes/b2/TempParts/single-document.php(15): the_content() #5 /www/wwwroot/kuajing.club/wp-includes/template.php(812): require('...') #6 /www/wwwroot/kuajing.club/wp-includes/template.php(745): load_template() #7 /www/wwwroot/kuajing.club/wp-includes/general-template.php(206): locate_template() #8 /www/wwwroot/kuajing.club/wp-content/themes/b2/single-document.php(104): get_template_part() #9 /www/wwwroot/kuajing.club/wp-includes/template-loader.php(106): include('...') #10 /www/wwwroot/kuajing.club/wp-blog-header.php(19): require_once('...') #11 /www/wwwroot/kuajing.club/index.php(17): require('...') #12 {main} thrown in /www/wwwroot/kuajing.club/wp-content/themes/b2/Modules/Common/Post.php on line 91