Autofilling food into a hunt, and then feeding your wolves, sometimes results in the food that's been filled into the hunt being used to feed your wolves. If you didn't have enough of that food type to feed your wolves with it and still have enough left over to fulfill the amount added to your hunt, this results in an inability to begin the hunt and an error popup. As there's not a convenient way to clear the auto-filled food from the hunt, the fastest way to fix the error is to refresh the page and start setting up the hunt from scratch.
I unfortunately don't have screenshots of this particular error at the moment, because the times it's come up I've been rushing to do my professions and it didn't occur to me to screenshot it until I had already exited out of the page. If I can reproduce it again I'll add screenshots.
