Fatal error: Uncaught Error: Interface "Tomsgu\PdfMerger\PdfCollectionInterface" not found in /var/www/html/includes/alpha/pdfmerger-050/vendor/tomsgu/pdf-merger/src/PdfCollection.php:13 Stack trace: #0 {main} thrown in /var/www/html/includes/alpha/pdfmerger-050/vendor/tomsgu/pdf-merger/src/PdfCollection.php on line 13