Fatal error on invoice generation

I got next error(debug) when generate invoice. No issue on packing slip.

Fatal error: Uncaught exception ‘Exception’ with message ‘Call to undefined method WPO\WC\PDF_Invoices\Legacy\Legacy_Functions::get_order_number1()’ in /home/yummygift/public_html/whole/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/legacy/class-wcpdf-legacy-functions.php:46 Stack trace: #0 [internal function]: WPO\WC\PDF_Invoices\Legacy\Legacy_Functions->__call(‘get_order_numbe…’, Array) #1 [internal function]: WPO\WC\PDF_Invoices\Legacy\Legacy_Functions->get_order_number1() #2 /home/yummygift/public_html/whole/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/legacy/class-wcpdf-legacy.php(52): call_user_func_array(Array, Array) #3 /home/yummygift/public_html/whole/wp-content/themes/ri-colias/woocommerce/pdf/Simple1/invoice.php(4): WPO\WC\PDF_Invoices\Legacy\WPO_WCPDF_Legacy->__call(‘get_order_numbe…’, Array) #4 /home/yummygift/public_html/whole/wp-content/themes/ri-colias/woocommerce/pdf/Simple1/invoice.php(4): WPO\WC\PDF_Invoices\Legacy\WPO_WCPDF_Legacy->get_order_number1() #5 / in /home/yummygift/public_html/whole/wp-content/plugins/woocommerce-pdf-invoices-packing-slips/includes/legacy/class-wcpdf-legacy-functions.php on line 46