Were you able to find any solution. I am also struck with the same problem. But i have anlayzed further and found that the BR Check User CanContribute To Kb on kb_knowledge is preventing from article creation. The issue we have CSM and HR modules active in our system which would require a user to have snc_internal role to create a knowledge article. This is true for admin user and as well as system updates. Please post if you were able to figure a way out for you scenario.
