Fatal error: Uncaught Error: Interface 'PDFEmbedder\Viewer\ViewerInterface' not found in /var/www/sweves.se/httpdocs/wp-content/plugins/pdf-embedder/src/Viewer/Viewer.php:15 Stack trace: #0 {main} thrown in /var/www/sweves.se/httpdocs/wp-content/plugins/pdf-embedder/src/Viewer/Viewer.php on line 15