I was retrieving a watery grave with Warly when a warning screen appeared, and my only option is to exit game 
Steps to Reproduce
I was playing Warly, I was carrying a doy doy, I think I also had 2 invisible speargun (another bug). I was driving a cargo boat. Not sure, but my inventory may have been full when I picked the grave (yeah, should have seen that before I tried to pick it in the first place, I know!). I had just killed a ghost from a previous watery grave. I was in hurricane season (around day 23). I was wearing a captain or pirate hat (don't remember). Well, that's all I can think about! Hope it can help!
I was playing Warly, I was carrying a doy doy, I think I also had 2 invisible speargun (another bug). I was driving a cargo boat. Not sure, but my inventory may have been full when I picked the grave (yeah, should have seen that before I tried to pick it in the first place, I know!). I had just killed a ghost from a previous watery grave. I was in hurricane season (around day 23). I was wearing a captain or pirate hat (don't remember). Well, that's all I can think about! Hope it can help!
A developer has marked this issue as fixed. This means that the issue has been addressed in the current development build and will likely be in the next update.