This is going to be a long post. There was an issue with Sims going to work and not coming back, even in the original game release. Usually you could just wait it out and they'd eventually return home. But if your game is crashing, there may be more to it than a random bug.
My first suggestion is get ffs lot debugger, aka the batbox. Use it to force errors on all, fix broken work states, nuke scenario controllers, etc. That may fix it. Even if it doesn't, this is a tool I recommend to everyone because you can use it to keep your game running smoothly in general. It deletes built up gossip, garbage, and stuck tokens, and fixes various issues that will pop up. That's why it was created.
My second suggestion is delete the family. Either acquaint yourself with SimPe or just do it the built in way. SimPe can be hard at first and can ruin your game if you aren't careful. But, there are tutorials and those of us that use it can help. I've been using the program for over a decade myself and started with tutorials and forum posts. You can use SimPe in conjunction with batbox to delete corrupted Sims and everything attached to them. This method is the best way because it doesn't leave anything behind.
If you don't want to mess with SimPe, there is the built in method via the Sim bin. Just move them into the bin and delete them from there. This doesn't corrupt your game directly and you'll probably be able to go on playing for a awhile before errors build up. If you start fresh periodically anyway, you will be fine. What this method does, is leave behind stubs and snippets related to the Sims you deleted. Besides just adding clutter that takes up space in your files, these snippets leave messed up memories behind and also get carried along on gossip between other Sims. Sims in Sims 2 gossip a lot, autonomously, and they will spread the snippets like an std. Sometimes you won't notice a problem until it starts causing lag, sometimes you'll see errors in thought bubbles or memories. In Sims 2, it becomes necessary to start fresh eventually because even if you do everything "right" clutter and errors start piling up (unless you use SimPe to keep it clean). Using this method to delete Sims just makes it happen faster.
My third suggestion is start completely fresh. Delete either the Sims 2 folder and generate a fresh one, or just delete the neighborhood you were in and replace it with a fresh copy from the program files.
