I've had a nightmare of PHP issues and json to serialization issues to fight through upgrading Magento 2.1.3 to 2.1.5, then on to 2.3.1, so I am pretty good with Magento, and Googling for answers, and am almost through the dark, but now am stuck when running:
php bin/magento setup:upgrade
(error)
Module 'Magento_Sales':
Notice: Undefined index: option_type in /var/www/vhosts/redostore.com/httpdocs/vendor/magento/module-sales/Setup/SerializedDataConverter.php on line 33
The line 33 referred to is: if ($option['option_type'] === 'file')
This gives me not a single clue as to what it wants from me, or why it's failing. I need a shove in the right direction on this one. Please help!
Centos 7, PHP 7.2
