Error Generating PDF

Hi,
I’m receiving this error suddenly today:-

Warning: file_put_contents(): Only 0 of 28456 bytes written, possibly out of free disk space in /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/vendor/dompdf/dompdf/src/Image/Cache.php on line 113

Fatal error: Call to a member function getData() on null
#0 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/vendor/dompdf/dompdf/src/Adapter/CPDF.php(986): Cpdf->selectFont(‘/home/sabertrio…’)
#1 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/vendor/dompdf/dompdf/src/FontMetrics.php(280): Dompdf\Adapter\CPDF->get_text_width(‘SABERTRIO SDN B…’, ‘/home/sabertrio…’, 16, 0, 0)
#2 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/vendor/dompdf/dompdf/src/FrameDecorator/Image.php(66): Dompdf\FontMetrics->getTextWidth(‘SABERTRIO SDN B…’, ‘/home/sabertrio…’, 16, 0)
#3 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/vendor/dompdf/dompdf/src/Frame/Factory.php(223): Dompdf\FrameDecorator\Image->__construct(Object(Dompdf\Frame), Object(Dompdf\Dompdf))
#4 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/vendor/dompdf/dompdf/src/Dompdf.php(813): Dompdf\Frame\Factory::decorate_frame(Object(Dompdf\Frame), Object(Dompdf\Dompdf), Object(Dompdf\FrameDecorator\Page))
#5 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-pdf-maker.php(53): Dompdf\Dompdf->render()
#6 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/documents/abstract-wcpdf-order-document.php(712): WPO\WC\PDF_Invoices\PDF_Maker->output()
#7 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/documents/abstract-wcpdf-order-document.php(747): WPO\WC\PDF_Invoices\Documents\Order_Document->get_pdf()
#8 /home/sabertrio/public_html/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/class-wcpdf-main.php(358): WPO\WC\PDF_Invoices\Documents\Order_Document->output_pdf(‘inline’)
#9 /home/sabertrio/public_html/wp-includes/class-wp-hook.php(287): WPO\WC\PDF_Invoices\Main->generate_pdf_ajax(”)
#10 /home/sabertrio/public_html/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(”, Array)
#11 /home/sabertrio/public_html/wp-includes/plugin.php(478): WP_Hook->do_action(Array)
#12 /home/sabertrio/public_html/wp-admin/admin-ajax.php(176): do_action(‘wp_ajax_generat…’)
#13 {main}

Pls assist.