I have Magento 126.96.36.199 and while I am able to establish a successful connection between Linnworks and Magento, the sytems fails to load Magento Categories.
I have already seen this article: https://help.linnworks.com/support/solutions/articles/7000005075-magento-configurator-not-loading-categories
This is not helping me...I am still unable to see categories.
Have you first tried to update the Magento channel in the listing software to pull in the categories? To do that:
1) If you work in the Net version > Settings -> General Settings -> Listings tab -> "Clear" button for Magento settings line.
2) If you work in the desktop/LinnLive -> from the Magento Configurators screen -> there is a drop down menu on the top panel to the right, where you can select your integrated Magento channel name -> there is "Update" button to the right of it - select the needed channel there and click the Update button to update the categories from that channel(img1).
It worked! (the Net Version).