If two dupes try to wrangle the same critter, you'll get a null reference deal that crashes the game; guessing one finishes before the other and the second shouldn't have started wrangling the same one in the first place. Worth noting this was with a couple hundred hatches in a 1x1 space and instant work mode on.
Your bug reporting system is way too much work on my end; I had to make an account and everything, but maybe that's the point. I tried to upload an actual log but the page crashed (not sure if it's y'all or my browser that kept my entry, but thanks), enjoy a grocery list from some time ago instead. Feel free to nab my save from your cloud instance
Have 100+ critters in a room, have multiple ranchers, wrangle them all, await null reference when dupe tried to finish wrangling a critter that's already wrangled/picked up.