This is now a bug in my game (no mods, vanilla game). I was using it fine in my amazon challenge just yesterday, but I started a history challenge today, and no dice, can't roast fish
I started the History challenge with a brand new copy of Sims 4, freshly downloaded/installed. Still running into this issue all the time. I've moved chairs away so they don't "lock" with the campfires. That allows Sims to sit, at least. But when I make them cook, I get failed routing messages OR one sims will be able to successfully cook. A second sim will get maybe halfway through cooking a fish, and then just gets up to do something else. The fish just disappears. Same thing with beetles. Before this bug started, sims didn't necessarily need chairs in order to cook, they can do all their cooking by kneeling in front of the fires. So there's an issue whether chairs are present or not. One sim started out kneeling to cook, then moved onto a seat and continued cooking. Her's worked. But it blocked the other sim from cooking. Also, even if some of this can be solved by moving chairs slightly farther away, that doesn't solve it for pre-made areas like the Hermit's house. My sims are never able to do anything at the pre-made fire pits near the waterfall for instance, and thats not an area anyone but EA can access. Causes a routing error message every time.
I had this issue in my game, but putting both the chair i had and the campfire into my inventory and then back out onto the ground fixed. Don't know if that will help anyone but it worked for me so I thought I would post it
As of June 2019 this is still happening. Not consistently either as I was playing earlier today and roasting by the fire worked fine. Logged back on and I can't do it. Tried both fire pits with no success.
I also have this problem. My sim can't get to the campfire to roast anything. I tried repairing the game and it didn't help. They could roast things if I add a chair (I chose the log stool and put it to the left of the fire) but then they got stuck on the chair and would wave about while sitting and cancel any Interaction I tried (walk here, go to bed, etc). I could free them by deleting the chair in build mode. Strangely enough I put the chair back but at the top end of campfire and Vladislaus Straud the vampire visited and autonomously roasted marshmallows on the chair then left. My sim so far doesn't get stuck with this new chair position either. Still can't roast without a chair though.
I still get this from time to time, too. Also, probably related, my Sims still have issues frequently with being able to extinguish fires that happen around the campfire. They can't route to it so I just have to wait until it burns out. They have no problems routing to extinguish fires that happen anywhere else on the lot.