Fatal error: Uncaught Error: Interface "PDFEmbedder\Viewer\ViewerInterface" not found in /home/successforkids/public_html/wp-content/plugins/pdf-embedder/src/Viewer/Viewer.php:14 Stack trace: #0 {main} thrown in /home/successforkids/public_html/wp-content/plugins/pdf-embedder/src/Viewer/Viewer.php on line 14