Fatal error: Uncaught Error: Class 'League\CommonMark\Block\Element\AbstractBlock' not found in C:\xampp\htdocs\admin\vendor\league\commonmark\src\Extension\TableOfContents\Node\TableOfContentsPlaceholder.php:17 Stack trace: #0 {main} thrown in C:\xampp\htdocs\admin\vendor\league\commonmark\src\Extension\TableOfContents\Node\TableOfContentsPlaceholder.php on line 17