Oddly enough, I encountered what looks to be a similar error yesterday - though not with Gilbert. My custom hood was created with the stealth hoods disabled, the anti-redundancy mods in, and no townies, so everybody is playable apart from the NPC waiters, cops, cashiers, firefighters and drivers. One of the Sims was low on social, so I had him email a couple of people and chat with someone on the base game computer. When I hit save at 6am the next morning, the game crashed. I did the same thing again, the game crashed again. I tried playing that day a third time, but used the Sim Blender to fill his social bar and didn’t let him interact with anyone, and was able to save successfully.

It’s going to take me a while to figure out who or what is the problem, since there are about 10 Sims if you include everyone who was online when he opted to chat, though only 3 if it was emailing that was the trigger event. But I’ll pass on anything I figure out.

Incidentally, it sounds like it’s the macOS log that you’ve been looking at, which is a stack dump of everything that was running on your machine at the time of the crash. I didn’t find much useful in mine, but mostly it’ll only tell you whether you’ve got a RAM problem or another program interfering with the game.

I see that we’re both running the 64-bit version of the game that was released in January (1.2.4), though you’re on High Sierra and I’m on Mojave. I’ve encountered a couple of weird new bugs with it, so if I hit the same crash conditions again I’m going to try copying the hood to an older Mac that still has the previous version of Sims 2 Super Collection and see if that does the same thing (as far as I can, given that the same day will never run the same way twice, though I can force chats and emails and phone calls to the same people).

I don’t have anything useful in the logs in The Sims 2 logs, but like an idiot I did another (successful) session in the game before thinking to go and look, so they cleared themselves down. I’ll check them immediately if I get another crash.