@LaurenTe It's possible that these saves are corrupted, not so much that the game can't recognize them as saves but enough that they can't be loaded. However, there are a couple things worth trying before giving up. The first is to check that you really do have all the same expansion packs installed and loading on the other computer. Start a new save, go into CAS or Buy mode, and click the button to filter by pack. You'll see each installed pack listed, so you should know right away if one is missing. Make sure you've installed all the store worlds you had before as well and that they're loading, i.e. you can start a new save in one and it actually loads properly.
The other thing to try is moving only the .nhd file from an old save, specifically the file for the sims' homeworld, into a folder for a new save that takes place in the same world. (This is the inverse of what you tried with the Meta.data file.) The other files within a save folder are replaceable with the exception of TravelDB.package, but that only has to do with foreign worlds. If sims in the previous save traveled at any point, I'd suggest adding NRaas ErrorTrap and Overwatch to clean up any stray data left stranded by the missing TravelDB, but you can wait until you find out whether the save actually loads this way. Or you can try adding back TravelDB in addition to the .nhd file, but please try the .nhd alone first.
If neither of these works, feel free to send me your save(s) via private message, and I'll see whether I can load them on either of my Macs. Please list the packs you own as well as any store worlds, and I'll mirror your content. If I can't load the saves, then it's likely they are in fact too corrupted to use.
