Fatal error: Uncaught Error: Class "Concrete\Core\Foundation\Command\Command" not found in /home/elcrestweb/public_html/concrete/src/Block/Command/AddBlockToPageCommand.php:10 Stack trace: #0 {main} thrown in /home/elcrestweb/public_html/concrete/src/Block/Command/AddBlockToPageCommand.php on line 10