Error Code 21916564
Selected category is not enabled for variation listings.
Solution
This error only occurs on variation products and usually means that either the category mapping of the relevant parent is missing or that eBay does not allow variation listing in the category you have already mapped.
Follow the steps below in StoreAutomator to see if your product's category mapping has been completed.
1- Go to eBay channel > Channel > Channel Products > Find the relevant Parent and click the Edit button under the Action tab.
2- The product editor will open and you can see whether the category has already been mapped or not as shown in the picture below.
In this case, you should map your local category to an eBay leaf category.
3- Go your eBay Channel > Channel > Mappings
4- Expand your local category and eBay categories by clicking on them
5- Map your local category to an eBay leaf category with the drag-and-drop method as shown below.
If your Local category is already mapped to another category and eBay does not allow variation listing in this category, remove the mapping on the relevant category by referring to the link below and map it to another eBay leaf category by following the steps above.