Fatal error: Could not check compatibility between Dompdf\Frame\FrameTree::getIterator(): Dompdf\Frame\FrameTreeIterator and IteratorAggregate::getIterator(): Traversable, because class Dompdf\Frame\FrameTreeIterator is not available in /var/www/app/dev/inc/dompdf/src/Frame/FrameTree.php on line 138