My current environment is Magento 2.4.2p1, Linux, PHP 7.4
I normally install the ShipStation extension by downloading the zipped folder and extracting it to app/code. I saw an updated composer package in the Magento Marketplace. Decided to install that using - composer require auctane/api. It downloads, installs and compiles without issue.
When I go to ShipStation.com and test my connection, it works Ok. Once, I click Connect, an error is thrown - an error occurred attempting to update orders: invalid xml. error: 'data at the root level is invalid. line 1, position 1.' we received: 'an error has happened during application run. see exception log for details.
ShipStation is unable to connect to the store. The Magento system.log file indicates an issue with the file Export.php at line 292.
main.CRITICAL: TypeError: Argument 2 passed to Auctane\Api\Model\Action\Export::addXmlElement() must be of the type string, null given, called in /home/public_html/vendor/auctane/api/Model/Action/Export.php on line 354 and defined in home/public_html/vendor/auctane/api/Model/Action/Export.php:292
I have an open ticket with support. I'll provide updates.
