After updating to El Capitan I cannot drag items from inventory into variations categories to create listings

I updated my OS to El Capitan. Now when I try to create multiple item listings, I cannot drag variations into place in the template (from the inventory). I can drag them but they go past where I aim them and will not drop. I have updated to the latest GS version and it did not fix problem. I checked existing multiple item listings and they cannot be edited - that is, I cannot drag even the same item into a spot. Nothing will drag and drop into multiple item template.