Hi Brian, thanks for reporting this bug.

This is a bug in the processing of curve intersections for intersection object snap. So it can potentially happen in anything that picks a point.

I've got it fixed up now for the next v3 beta.

It's actually a bit different than a regular crash bug - this one is a warning that something was not structured as expected in the intersection results. But it actually happens that the messed up result is not actually used so it is possible to just ignore this particular one - unlike a regular crash bug this kind of warning message popup has an "ignore all" button that you can push and you should actually be able to continue running MoI ok after doing that.

Also this is far more likely to be triggered when calculating the intersection on projected curves, so if you keep running into it you could turn off projected intersections until the next v3 beta. That's under Options > Snaps > Object snap options > "use apparent intersections".

Thanks,
- Michael