PHP error in 1.9.105 took site down

Free version 1.9.105 auto-updated on the site 2 hours ago and took down both front end and admin.

Here’s an example of the logged error:

PHP Fatal error:  Uncaught Error: Call to undefined function gpls_woo_rfq_is_account_page() in /var/www/vhosts/redacted/httpdocs/wp-content/plugins/woo-rfq-for-woocommerce/woo-rfq-for-woocommerce.php:517\nStack trace:\n#0 /var/www/vhosts/redacted/httpdocs/wp-includes/class-wp-hook.php(310): GPLS_WOO_RFQ->gpls_4woo_quote_wp_init()\n#1 /var/www/vhosts/redacted/httpdocs/wp-includes/class-wp-hook.php(334): WP_Hook->apply_filters()\n#2 /var/www/vhosts/redacted/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action()\n#3 /var/www/vhosts/redacted/httpdocs/wp-settings.php(632): do_action()\n#4 /var/www/vhosts/redacted/httpdocs/wp-config.php(88): require_once('/var/www/vhosts...')\n#5 /var/www/vhosts/redacted/httpdocs/wp-load.php(50): require_once('/var/www/vhosts...')\n#6 /var/www/vhosts/redacted/httpdocs/wp-blog-header.php(13): require_once('/var/www/vhosts...')\n#7 /var/www/vhosts/redacted/httpdocs/index.php(17): req...', referer: https://redacted/

Site loads fine with plugin disabled. We are going to try rolling back a couple of versions.