Can no longer craft leather

1. I selected the Leather recipe in the tanning station
2. I set the number next to "Craft" to 20, which was as high as it would go
3. I selected "Craft" and proceeded to craft leather as expected
4. When I tried to repeat the process, I could select the Leather recipe and the animal hides and curing salt would appear under "Crafting Inventory", but the quantity counter and the "Craft" button remained greyed out. I collected more animal hides and bought more curing salt. Exited and re-loaded the game. Traveled to different cities and used different tanning stations and the game still won't allow me to craft leather.

 

Is your tanning knife worn out?

 

That was it. Thanks! I purchased a new tanning knife, but still had the old worn out tanning knife equipped.