I've only been troubleshooting with the base game at this point, so the complications with expansion packs should be taken care of.
I looked for the files mentioned (the files that could be lingering after an incomplete installation -- like the "transgaming" files). I couldn't find any via Finder. Perhaps it's possible that they're hiding somewhere. I'm not sure. I looked in the obvious places within finder and did a search. No dice.
I tried reinstalling the game with Origin so that I could use their "repair" feature. For whatever reason, it's offered for my Sims 4, but not for Sims 3. I have the newest version of Origin and all that. No, again, no dice there.
Graphics don't seem to be an issue. My computer isn't on the list of problematic computers, and I know that the game was able to start previously. Remember, the first issue was the "no disc" error once at the cusp of playing (at the pick-a-household stage). I've gotten that on other Macs and have fixed it. So, in other words, my computer went through all the initial scenes and the loading processes without a problem. The game worked perfectly fine up to this point. Graphics were great. Speed was normal. Everything was working fine. I wish I could get back to this original error, and I don't know why I can't. That seems strange to me, and it's something to ponder. I was getting that error, why can't I get that error again? What's different now? The "no disc" error prior to picking a household seems like a simpler error to deal with--I think I'd prefer it.
I've tried the SuperPatch without the launcher update. The game launcher opens (when installed by disc, not by origin) prior to ANY update. Both the launcher update and the manual patch installation lead to the unknown error. Though, they both seem to complete their installation.
Here are some of my computer specs... I checked for updates, but none are available.
I find it hard to believe that my computer would be incapable of playing the game. I've always had macbooks (different types, even), and it's always been fine. I get that it's maybe not ideal, but it's always worked. Plus, this computer was previously able to start the game up (and did so well). Clearly, there's some other issue if I can't even get back to that stage. Maybe the first question isn't even so much about what's preventing the game from playing, but about why the error has changed when, seemingly, the conditions are the same as they were when the first error occurred. Clearly, though, that's not the case. Something's gotta be different--unless, for whatever reason, expansion packs would actually aid in the initial loading of the game(?) That would explain why parts of the game can load--like an intro potentially provided by an expansion pack without the aid of the base. I don't know if that's the case, though.
I'd buy into the possibility of a corrupt file hiding somewhere. That's making the most sense to me. But in that case: where?! My finder seems to be hiding files from me. I tried to reveal all files with a code in Terminal. I still didn't find any missing Sims files. I just feel like there have been discrepancies between what I see in Finder and what I see when I use the search tool in Finder. That being said, I did use a full installer with CleanMyMac. But, perhaps it doesn't know what to look for with something like the Sims. I'm not sure.
@fluffyvmpr A couple of small things to note: First, macbook airs and macbook pros, if that's what you've had in the past, are very different. Pros have better hardware and cooling and are spefically designed to run more resource intensive programs, while airs are supposed to be lightweight and portable. You're right that your particular mac meets minimum requirements for the game, but it could still struggle to run the heaviest-hitting EPs. (Still, if you're unable to launch even the base game, that can be put aside.) Second, EA hasn't updated the game in years, so mac OS has become increasingly incompatible with TS3. The disc authentication failure and unknown error messages didn't become common until the release of El Capitan. I don't know when you last played, or what OS you were running, but it's not surprising that you'd have more trouble with TS3 now than before.
As for the files you need to delete after an uninstall, the Finder won't be able to locate them for you, as they're too far down into subfolders for the search to work. That's why Bluebellflora's guide is so useful—just follow the instructions and trash every file on the list.
https://bluebellflora.com/how-to-do-a-clean-uninstall-and-reinstall-on-a-mac/
Once you've uninstalled, reinstalled the base game through Origin, and patched, it's probably a good idea to drag your TS3 game folder, if you still have one, out of Documents\Electronic Arts and onto your desktop. You wouldn't be able to find this folder in a Finder search either, as the EA folder is hidden. But it would have been generated when you first launched the game, and it conceivably could be causing issues now. If there's no game folder in Documents\EA, the game will generate a new one with no content in it. By the way, this is called the clean folder test, and it solves a lot of problems with games that are lagging or failing to load.
Anyway, at this point, it's probably best to just complete these four steps (uninstall using Bluebellflora's guide, reinstall through Origin, run the Super Patch, and remove your game folder, if you have one). and then see if you can launch and play for a bit. Whether this works obviously dictates the next step(s), but either way, post back and we can go over what to do.
