I have downloaded a non-steam trinity from the stardock downloads page(https://store.stardock.com/myaccount/products)
if you registered your sins trinity with stardock you should be able to log in to the store on the above link and download the FULL installer (the update is (from memory) only for the 1.3x to 1.37 not for earlier than that)
hope this helps
Thanks for the suggestion Harpo.
Unfortunately, when I log into my account, my game listings are apparently all messed up. Some claim I can download them directly, but when I try I get various website errors (404 page not found, etc.). Other games claim I have to use the Gamestop PC App. I bought all these from Stardock, not Gamestop! Why can't I download them here?
I bought the original Sins when it was first released years ago at retail (physical copy) and it's not even listed (even though I registered it to get updates). However, the two expansions I bought from Stardock are listed, but claim I have to use the Gamestop app.
Of course Gamestop has removed the ability to archive your games, preventing you from backing them up. This is one of the reasons I don't trust "services" like them and Steam, they can change/remove whatever they want anytime. What a mess!