"No Game Disc Found!" Sims 3 Pets w/ Origin Sims 3 Base game

I've searched for a few hours now for the answer to this problem but cannot find anyone who had successfully installed a G4TW Sims 3 Pets over the top of an Origin Sims 3 Base Game.

I installed Sims 3 via Origin a few days ago, I no longer have the CD, so I'm unable to install without Origin. Today I downloaded Pets via this website along with the Ultimate Fix and the Manual Patch. I followed each step correctly, then opened the launcher after cracking the game in "C:\Program Files (x86)\Origin Games\The Sims 3\Game\Bin" (with the correct crack for Pets) but when I tried to the launch the game it opened up Origin and gave me the "No Game Disc Found!" error.

I've tried a few other things attempting to get it working but still nothing. I'd just like to know if there's a fix for this, if having the sims 3 base game in the Origin folder and then the Pets expansion in the Electronics art folder is maybe the problem? or if it's just not possible to play with Origin?

Okay, thank you for the confirmation. I feared as much. I was lucky enough to find a iso copy of the base game on an old computer. They're all from G4TW so they should work perfectly together. I'll post again if I have any problems. Can't wait to play!

Sorry to intrude, I have the same "no game disc" problem with Sims3 University Life. My base game was installed by disc through Origin, and I have two other expansions I purchased through Origin. For this downloaded expansion to work I get the impression I need to re-download the base game from here, but will that mean my current expansions won't work? Will I need to re-download all my games from G4TW in order for it to work?