WP Mail stopped working with Gmail SMTP

Replies: 3

In the main setup screen for WP Mail SMTP under the General Tab, I see…
(Also: Using Gmail for Mailer configuration)

Mail

From Email – There has been a critical error on your website. Please check your site admin email inbox for instructions.

I enabled Debug and Logging and get these errors.

[16-Aug-2020 18:27:17 UTC] PHP Fatal error: Uncaught Error: Call to undefined function GuzzleHttp\Psr7\get_message_body_summary() in /home/wp_6ntqyx/bcha.org/wp-content/plugins/wp-mail-smtp/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php:127
Stack trace:
#0 /home/wp_6ntqyx/bcha.org/wp-content/plugins/wp-mail-smtp/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php(107): GuzzleHttp\Exception\RequestException::getResponseBodySummary(Object(GuzzleHttp\Psr7\Response))
#1 /home/wp_6ntqyx/bcha.org/wp-content/plugins/wp-mail-smtp/vendor/guzzlehttp/guzzle/src/Middleware.php(65): GuzzleHttp\Exception\RequestException::create(Object(GuzzleHttp\Psr7\Request), Object(GuzzleHttp\Psr7\Response))
#2 /home/wp_6ntqyx/bcha.org/wp-content/plugins/wp-mail-smtp/vendor/guzzlehttp/promises/src/Promise.php(203): GuzzleHttp\Middleware::GuzzleHttp\{closure}(Object(GuzzleHttp\Psr7\Response))
#3 /home/wp_6ntqyx/bcha.org/wp-content/plugins/wp-mail-smtp/vendor/guzzlehttp/promises/src/Promise.php(156): GuzzleHttp\Promise\Promise::callHandler(1, Object(GuzzleHttp\ in /home/wp_6ntqyx/bcha.org/wp-content/plugins/wp-mail-smtp/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php on line 127