Fatal error: Uncaught Error: Undefined constant "Patchwork\Utf8\MB_OVERLOAD_STRING" in /home/.sites/59/site1329/web/phpBB3/vendor/patchwork/utf8/src/Patchwork/Utf8/Bootup.php:45
Stack trace:
#0 /home/.sites/59/site1329/web/phpBB3/includes/utf/utf_tools.php(28): Patchwork\Utf8\Bootup::initMbstring()
#1 /home/.sites/59/site1329/web/phpBB3/common.php(97): require('/home/.sites/59...')
#2 /home/.sites/59/site1329/web/phpBB3/viewforum.php(20): include('/home/.sites/59...')
#3 {main}
  thrown in /home/.sites/59/site1329/web/phpBB3/vendor/patchwork/utf8/src/Patchwork/Utf8/Bootup.php on line 45