Ah, my Mac OS is 10.9.5 and GS7 wants 10.10 or above… I’m avoiding updating my OS for as long as possible as I will lose some earlier Adobe apps that I rely upon.
It is totally to understand that you don’t want/can upgrade your OS X.
Unfortunately, older versions of GarageSale are no longer compatible to the eBay system due to the changes eBay made recently.