Normally they are both available at the same time, and these two quests are needed for the goat invasion quest to happen~
Okay, I restarted and was able to do the rolling stone quest. At this point I haven't yet talked to Lothar to start the investigation, but I have done some quests that involve crafting some things, right now I'm doing the one where we harvest in the field and get 3 rosemary for Cane. Are those in a map that I'll find later?