32 bit save crashes after converting game to 64 bit

@calicogirl12  Have you confirmed that all of your packs are installed in the 64-bit version?  What you've described would not be surprising if you were missing an EP that you'd previously had present when playing this save.

Yes I believe so

@calicogirl12  Still, please check, because again, this would be the expected result, or at least one of them, if you didn't have all your expansions installed.  Stuff packs and store worlds are less critical, unless of course the save takes place in that world, but it's worth checking too.  The missing objects warning could come from an expansion or stuff pack or missing store content, or custom content for that matter.

If that's not the issue, I can take a look at your save if you want.  Feel free to upload it somewhere and send me the link either here or via private message.  Saves are located in Documents > Electronic Arts > The Sims 3  > Saves.

Hmmm, what's odd is that the launcher tells me all of the expansions are installed and the game otherwise behaves as if all the expansion packs were installed, but an external installer never opened and there are no applications for each of the expansion packs like there were before I switched to 64 bit. Origin believes they are installed too, I checked the downloads cache. I don't think the save is the problem because it was perfectly playable once I managed to somehow get past the missing objects problem... The launcher also refuses to install multiple store items I used to have, it will install them and then when I quit the launcher the items disappear. I'm wondering if I should just give up on this old save.

@calicogirl12  The 64-bit version of Sims 3 is installed differently: no external installer, no expansion pack folders buried within the .app.  The packs are now installed in a "The Sims 3 Packs" folder either in Applications or in Users > your username > Applications.

The store content disappearing can be caused by iCloud uploading the contents of Documents to cloud storage, although there are other causes as well.  If you'd like to troubleshoot it as well, let me know.

I'd still be happy to take a look at your save, if you want, but I understand not everyone is comfortable sharing.  It's a bit difficult to say whether the underlying issue is save corruption, or something about the missing objects, or something that doesn't work well in the 64-bit version, e.g. playing with the Pets EP on integrated Intel graphics chips.  But some of these issues are not really solvable: save corruption may or may not be reversible, and removing Pets would make a save unplayable anyway.