I have the same problem as above, when I click on a spell it shows 'No roll allowed as you have no chance of success'.
However, when I set the 'Sub-Type' at the skill 'Magic' to Magic, I can no longer enter 'Skill Chance', this automatically becomes 0 every time.
For example, I can type in 60 at Skill Chance, but when I then enter, this automatically becomes 0 again. If I set the Sub-Type to None, the 60 appears.
What am I doing wrong here?