@evelienbaumans There's a version of ErrorTrap available for patch 1.67, two actually, since the disc and Steam installs have different internal build numbers. If you look at the download page, you'll see two download buttons for patch 1.67, one each with the Steam and Origin icons.
If that doesn't help, what you could try is using MasterController to add your sims to another house in the world, that is if there's enough data left of them. I'm not sure if you did exactly this before, but here, the key is to add them to a house you're not playing (it can be empty, use "save as" to rename your save, quit without switching households, delete the cache files, reload, and see whether you can now switch to your main sims. A MasterController town reset (NRaas > MC > Town Options > Reset Everything) before you switched wouldn't hurt either.
Even if you can't switch to them, you can try saving their household to the library. At the very least, you'd have an intact copy of the sims to place in a new save. If you also want to preserve the house, save it separately. Quit to desktop and delete the cache files before loading the new save where you'll be placing your sims and/or their house.
As far as useful mods go, ErrorTrap and Overwatch are the best way to keep your save healthy in the long run. MC town resets are helpful too; most of us who use the mod run one every ~8 sim-weeks, plus or minus. Depending on which expansions you have in play, Traveler, Register, and Traffic can also be extremely useful, and it certainly wouldn't hurt to add any or all of them. That's it for the mods that address corruption, although others have useful functions too. I wrote up some descriptions here, if you're interested:
https://answers.ea.com/t5/Technical-Issues-PC/Sims-3-Common-Game-Fixing-Mods-Hero-Approved/m-p/9836847#M244207
