I bought Craftable Furniture by Shapescape. I see the "loading resources" screen and the "generating world" screen and then receive the message, "The software was closed because an error occurred." All other resource packs load and do not present the error. 

You cannot just resolve an issue that has not been resolved. I paid for this specifically to work on our realms servers for our nintendo switches and it does not. Of course mojang will not REFUND this. So you are going to fix this or remove it from the market place.