Thanks for the links. I looked at the first one already and I don't think it's the same issue, because I've been doing some experimenting. This is a brand new embark so I thought of some ways to test things. There are only 3 tasks right now- digging, moving everything to an 'all' stockpile, and gathering plants in a zone outside the entrance.
1. I loaded the fort and let it go with a stopwatch running, in about 2.5 mins it crashed.
2. I loaded it again and put everyone in a burrow, no crash at 2.5 mins so I let them out of the burrow, within another 2 mins it crashed.
3. I loaded it again and disabled the zone, it crashed in about the same amount of time.
4. I cancelled the mining but left the zone and stockpile. crashed in about 3 mins
5. Immediately crashed before unpausing when I used the F1 hotkey (wtf?)
6. Set a burrow over the wagon & add everyone to it intending to let go indefinitely this time and crashed within seconds of unpausing...
7. Same as 6, at least it's consistent...
8. disabled the stockpile and did nothing else, ran for over ten mins without issue before I stopped it to try something else
9. Set Burrow over wagon, add everyone to it and disable stockpile, crash within seconds
10. Set zone to inactive, cancel the mining, leave stockpile on- crashed at 7 minutes
11. Set zone to inactive, cancel the mining, disable stockpile. no crash.
So as far as I can tell it looks like two things are crashing it, burrowing everyone over the wagon will for unknown reasons and the stockpile is the second cause.
I've never raided in this world so it can't be equipment corruption, and the date is inconsistent so it's not a birth bug. I tried the fix-equipment script anyway it didn't do anything. I looked through my stocks and there is nothing unusual in there that might cause an issue.
I posted the save if anyone wants to look at it. I guess tomorrow I can try changing the stockpile settings to narrow it from here.