In Magento ver. 2.2.4 when I try to make a payment with a credit card or by Bank Transfer this exception is generated. With PayPal this does not happen and I can place orders without problems.
2018-07-11 13:50:40] main.CRITICAL: Rolled back transaction has not
been completed correctly. {“exception”:”[object] (Exception(code: 0):
Rolled back transaction has not been completed correctly. at
/home/wwwdos9/public_html/…/vendor/magento/framework/DB/Adapter/Pdo/Mysql.php:270)”}