Fatal Error

Hello,

After last update my website got a blank page after changing delivery status. I think it affects payment, too.

Here is woocommerce log.

2021-01-29T01:23:47+00:00 CRITICAL Uncaught Error: Call to a member function getHeadersArray() on string in /var/www/wordpress/wp-content/plugins/post-smtp/Postman/Postman-Mail/Zend-1.12.10/Mail/Transport/Abstract.php:285
Stack trace:
#0 /var/www/wordpress/wp-content/plugins/post-smtp/Postman/Postman-Mail/Zend-1.12.10/Mail/Transport/Abstract.php(309): Postman_Zend_Mail_Transport_Abstract->_buildBody()
#1 /var/www/wordpress/wp-content/plugins/post-smtp/Postman/Postman-Mail/Zend-1.12.10/Mail.php(1209): Postman_Zend_Mail_Transport_Abstract->send(Object(Postman_Zend_Mail))
#2 /var/www/wordpress/wp-content/plugins/post-smtp/Postman/Postman-Mail/PostmanZendMailEngine.php(183): Postman_Zend_Mail->send(Object(Postman_Zend_Mail_Transport_Smtp))
#3 /var/www/wordpress/wp-content/plugins/post-smtp/Postman/PostmanWpMail.php(236): PostmanZendMailEngine->send(Object(PostmanMessage))
#4 /var/www/wordpress/wp-content/plugins/post-smtp/Postman/PostmanWpMail.php(60): PostmanWpMail->sendMessage(Object(PostmanMessage), Object(PostmanEmailLog))
#5 /var/www/wordpres in /var/www/wordpress/wp-content/plugins/post-smtp/Postman/Postman-Mail/Zend-1.12.10/Mail/Transport/Abstract.php on line 285

Thanks,
JiYeon