Error 500 when applying coupon on custom product or excluded product

Hi,

Loving the addon, but found a bug. When adding a product manually to the basket (by clicking the top left +) and then applying a coupon pos crashes with an error 500.

Having looked into the apache logs I found the following:

PHP message: PHP Fatal error: Uncaught Error: Call to a member function is_type() on bool in /var/www/vhosts/finecharmingnails.be/httpdocs/wp-content/plugins/woocommerce/includes/class-wc-coupon.php:875\nStack trace:\n#0 /var/www/vhosts/finecharmingnails.be/httpdocs/wp-content/plugins/woocommerce/includes/class-wc-discounts.php(329): WC_Coupon->is_valid_for_product()\n#1 /var/www/vhosts/finecharmingnails.be/httpdocs/wp-content/plugins/woocommerce/includes/class-wc-discounts.php(262): WC_Discounts->get_items_to_apply_coupon()\n#2 /var/www/vhosts/finecharmingnails.be/httpdocs/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-order.php(1132): WC_Discounts->apply_coupon()\n#3 /var/www/vhosts/finecharmingnails.be/httpdocs/wp-content/plugins/woocommerce/includes/rest-api/Controllers/Version3/class-wc-rest-orders-controller.php(84): WC_Abstract_Order->apply_coupon()\n#4 /var/www/vhosts/finecharmingnails.be/httpdocs/wp-content/plugins/woocommerce/includes/rest-api/Controllers/Version3/class-wc-rest...', referer: https://finecharmingnails.be/pos/?fbclid=IwAR2MDyQmfJ8J_LtZQ2NSJqWnHTaNjnl995qEoSozdJaZeG2PLS-tjZP8g_M

Any idea how to get this fixed? Or is this a shorcoming from woocommerce itself and not POS. Seems the same error is trown when a product is added that is excluded from the coupon use.

Debug:

Array
(
    [SERVER_SOFTWARE] => Apache
    [REQUEST_URI] => /wp-admin/edit.php?post_type=pos-station&page=pos
    [USER] => finecharmingnails
    [HOME] => /var/www/vhosts/finecharmingnails.be
    [SCRIPT_NAME] => /wp-admin/edit.php
    [QUERY_STRING] => post_type=pos-station&page=pos
    [REQUEST_METHOD] => GET
    [SERVER_PROTOCOL] => HTTP/1.0
    [GATEWAY_INTERFACE] => CGI/1.1
    [REMOTE_PORT] => 49068
    [SCRIPT_FILENAME] => /var/www/vhosts/finecharmingnails.be/httpdocs/wp-admin/edit.php
    [SERVER_ADMIN] => [no address given]
    [CONTEXT_DOCUMENT_ROOT] => /var/www/vhosts/finecharmingnails.be/httpdocs
    [CONTEXT_PREFIX] => 
    [REQUEST_SCHEME] => https
    [DOCUMENT_ROOT] => /var/www/vhosts/finecharmingnails.be/httpdocs
    [REMOTE_ADDR] => 78.23.15.52
    [SERVER_PORT] => 443
    [SERVER_ADDR] => 85.214.174.39
    [SERVER_NAME] => finecharmingnails.be
    [SERVER_SIGNATURE] => <address>Apache Server at finecharmingnails.be Port 443</address>

    [PATH] => /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
    [HTTP_COOKIE] => wordpress_sec_fa5ffbbf387f6f94456b59dbab99b372=rousseauxy%7C1623068956%7CkBji6YlPKyyDp3E5iAxxjfJsR6lqQR6xx5y7mMrZVXj%7C339485bdd95934333dbf71eed99574ea96c47e50ad3222529462083fecc60ddf; vchideactivationmsg=1; vchideactivationmsg_vc11=6.6.0; tk_ai=woo%3AuFdzABrNiaH%2B8l9bArl6D%2BLS; wp-settings-1=editor%3Dtinymce%26libraryContent%3Dbrowse%26urlbutton%3Dnone%26hidetb%3D1%26wplink%3D1%26imgsize%3Dfull%26edit_element_vcUIPanelWidth%3D617%26edit_element_vcUIPanelLeft%3D1066px%26edit_element_vcUIPanelTop%3D74px%26panel_vcUIPanelWidth%3D649%26panel_vcUIPanelLeft%3D1057px%26panel_vcUIPanelTop%3D74px%26advImgDetails%3Dhide; wp-settings-time-1=1615795193; __utmc=88300556; __utmz=88300556.1617308833.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); __utmv=88300556.|1=logged-in=no=1; wordpress_test_cookie=WP%20Cookie%20check; __utma=88300556.1134398016.1617308833.1619220481.1619719121.6; woocommerce_recently_viewed=15566%7C17245%7C16203%7C15908%7C17091%7C17591%7C16418%7C17936%7C18986%7C16058%7C16073%7C8677%7C19458%7C19063%7C17472; wordpress_logged_in_fa5ffbbf387f6f94456b59dbab99b372=rousseauxy%7C1623068956%7CkBji6YlPKyyDp3E5iAxxjfJsR6lqQR6xx5y7mMrZVXj%7C0795d466e63eced8abd93334100b2683b6638c48d07ffaea0683fbdb184de271; wccpprocookie=excludethispage
    [HTTP_ACCEPT_LANGUAGE] => nl-BE,nl;q=0.9,en-BE;q=0.8,en;q=0.7,nl-NL;q=0.6,en-US;q=0.5
    [HTTP_ACCEPT_ENCODING] => gzip, deflate, br
    [HTTP_REFERER] => https://finecharmingnails.be/wp-admin/edit.php?s=start&post_status=all&post_type=product&action=-1&seo_filter&readability_filter&product_type&stock_status&fb_sync_enabled&paged=1&action2=-1
    [HTTP_SEC_FETCH_DEST] => document
    [HTTP_SEC_FETCH_USER] => ?1
    [HTTP_SEC_FETCH_MODE] => navigate
    [HTTP_SEC_FETCH_SITE] => same-origin
    [HTTP_ACCEPT] => text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
    [HTTP_USER_AGENT] => Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36
    [HTTP_UPGRADE_INSECURE_REQUESTS] => 1
    [HTTP_SEC_CH_UA_MOBILE] => ?0
    [HTTP_SEC_CH_UA] => \" Not;A Brand\";v=\"99\", \"Google Chrome\";v=\"91\", \"Chromium\";v=\"91\"
    [HTTP_CONNECTION] => close
    [HTTP_X_ACCEL_INTERNAL] => /internal-nginx-static-location
    [HTTP_X_REAL_IP] => 78.23.15.52
    [HTTP_HOST] => finecharmingnails.be
    [proxy-nokeepalive] => 1
    [HTTPS] => on
    [PASSENGER_DOWNLOAD_NATIVE_SUPPORT_BINARY] => 0
    [PASSENGER_COMPILE_NATIVE_SUPPORT_BINARY] => 0
    [HTTP_AUTHORIZATION] => 
    [SCRIPT_URI] => https://finecharmingnails.be/wp-admin/edit.php
    [SCRIPT_URL] => /wp-admin/edit.php
    [FCGI_ROLE] => RESPONDER
    [PHP_SELF] => /wp-admin/edit.php
    [REQUEST_TIME_FLOAT] => 1622897986.2547
    [REQUEST_TIME] => 1622897986
)