I've tried 3 times to update the coop - I wasn't sure it was causing the crash the first time, thought it was random. The crash happens at end of day. I do not have the automated chests so I knew it wasn't that bug. I tried to repeat other things I had done that day. Clearing out kelp, donating to museum, etc. Those days worked out fine. But every time I ask to upgrade my coop into the second tier the game crashes at end of day. I made sure this third time to do basically nothing else important that day so I'm pretty sure its related.
I'll try again in spring incase its season + coop related. Currently I'm in winter.