Fix by adding the following into recipes.yml:
#1 oak log -> 4 oak planks

oak_wood_planks:
type: shapeless
ingredients:
log: [1, 'minecraft:log']
result: [4, 'minecraft:planks']

I'm not having this issue. Can you share what other plugins you're using? Also try this on a test server with only FastCraft+ to see if it is still a problem.