So, we've been playing a bunch of "Learn how the game works" runs. Anyway, we'd let the game sit for a few days, but when we went to open it today we checked on our research projects and none of them whatsoever were happening. At first we thought they'd just finished and we could assign new scientists, but we quickly realized that there weren't any scientists to do that with. Then we checked the leaders tab, and they were all gone. Scientists, naval officers, civ admins, ground force commanders, ALL of them.
Needless to say that run's being scrapped, but this is an extremely demoralizing issue and we're worried about it happening again.