Variations not enabled for category
eBay restricts variations for some of its categories. For some of the categories, the following error can appear:
The specified listing category does not support multi-variation (multi-SKU) listings
There are a couple of ways to resolve this.
A simple way is to change the eBay category to another one. Often the same product can be placed in a few different categories, so you can try changing categories without changing anything else. Go to the Creation Profile and set the same mapping to a different eBay category, save changes, and send the product again.
If products have only one variation, Salestio has a quick fix. Go to the Ebay Profile and disable the “Send the product with variation” option. This way, Salestio will send the item to eBay as if it didn’t have variations.