I'm having a similar issue and thought I'd just tack on here.
I want to buy a couple of the expansions through origin while they are one sale, but I bought the base game plus all of my other content through steam. I want to make sure I can use the expansions if I buy them and find out if theres a way that might convert the game from steam to origin where I don't lose my exisiting town.
Thanks.
I lost everything while attempting to migrate.
And still can't figure out what to do.
So I know nothing about Steam and this problem, but I found this "answer" (from here: http://forum.ea.com/eaforum/posts/list/9048450.page)
"You can transfer your Sims 3 from Steam to Origin. You have to delete your Steam install, take the product key, and enter in on Origin. Then you can download the game on Origin, where it will work without any issues with any future expansions you buy on there."
I'm not sure if yall have tried that out or what exactly you've already tried, but maybe this will help.
I have actually tried this.
It downloaded on Origin but when you went to install it, it would only go as far as choosing your country.
Then the install would crash.
I tried using my cousin's hard copy of the game to see if I could just use the Product Code but it won't even let me enter the key. Then when I load the Launcher it says it's a unregistered copy of the game.
So I went and downloaded the Sims 3 + Supernatual pack. I'm hoping this will help with the base game issues at least.
I was over a month dealing with the "specialists", and they couldn't fix my game.
I fixed it myself, finally:
1. Download d3dx9_31.dll from the internet somewhere
2. Place it in The Sims 3\Game\Bin folder.
Simple. 🙂
I actually got off the phone with Customer Service, they'll reset your codes so that the game is compatible with Origin.
