Fatal error: Uncaught Error: Using $this when not in object context in /opt/lampp/htdocs/tre-ext.sigmabiomedical.com/site/app/Vendor/mpdf/config.php:4 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/tre-ext.sigmabiomedical.com/site/app/Vendor/mpdf/config.php on line 4