Fatal error: Uncaught Error: Undefined constant "IMG_PNG" in /var/www/html/lib/jpgraph-3.0.7/src/jpgraph_errhandler.inc.php:282 Stack trace: #0 /var/www/html/lib/jpgraph-3.0.7/src/jpgraph_errhandler.inc.php(156): JpGraphErrObjectImg->Raise('The installed P...') #1 /var/www/html/lib/jpgraph-3.0.7/src/jpgraph_errhandler.inc.php(161): JpGraphException->Stroke() #2 [internal function]: JpGraphException::defaultHandler(Object(JpGraphExceptionL)) #3 {main} thrown in /var/www/html/lib/jpgraph-3.0.7/src/jpgraph_errhandler.inc.php on line 282