At this point I can't tell what's wrong with crafting, other than "something broke badly".

I made a new game, and was able to (with a crafting skill of 0) combine an arrow-shaft and an explosive arrowhead to create an Explosive Arrow.

After saving and then loading the game a few minutes later, I was no longer able to combine arrow-shafts and explosive arrowheads. For some unknown reason it just no longer works.

At this point I combined another branch and a pocket-knife and created another arrow-shaft. Then I put 1 point into my crafting skill, raising it from "0" to "1". After doing that I can no longer combine a branch and a pocket-knife to create an arrow-shaft.

This is repeatable. I've loaded the game up several times and repeated these same steps and I lose the ability to create an arrow-shaft every time I apply a point to my crafting skill.

That said, the problem goes beyond that. I could not apply the arrow-shaft to a poisoncloud arrowhead until I raised my crafting skill from "0" to "1". However, after reloading and trying to repeat this process I couldn't repeat that success even after raising my crafting skill back to 1.

I am very confused at this point.