Fatal error: Uncaught Error: Undefined constant "MB_OVERLOAD_STRING" in /home/subbless/suble.jp/public_html/mautic/vendor/joomla/string/src/phputf8/utf8.php:38
Stack trace:
#0 /home/subbless/suble.jp/public_html/mautic/vendor/composer/autoload_real.php(66): require()
#1 /home/subbless/suble.jp/public_html/mautic/vendor/composer/autoload_real.php(56): composerRequire64028ca246febaaa9cba785d29560035('2fb9d6f23c8e8fa...', '/home/subbless/...')
#2 /home/subbless/suble.jp/public_html/mautic/vendor/autoload.php(7): ComposerAutoloaderInit64028ca246febaaa9cba785d29560035::getLoader()
#3 /home/subbless/suble.jp/public_html/mautic/app/autoload.php(15): require('/home/subbless/...')
#4 /home/subbless/suble.jp/public_html/mautic/index.php(19): require_once('/home/subbless/...')
#5 {main}
thrown in /home/subbless/suble.jp/public_html/mautic/vendor/joomla/string/src/phputf8/utf8.php on line 38