WowAce

What is the nature of the defect?

I have gnomeworks open to level enchanting. I'm doing bracer - Lesser spirit. I learn Gloves - Mining. When I try to do lesser spirit it keeps giving me the error, missing the reagent 'fire oil' which isn't needed for this enchant. It turns out that it is needed for the one listed above, Cloak - Lesser Fire Res. I closed gnomeworks and reopened it. Gloves mining was now showing at the top of the list and all enchants were again working correctly.

What (if anything) triggers the defect?  (happens when loading, when activating the mod, when clicking a particular button, etc)
See above.

Please post any error messages associated with the defect.

I levelled a few alts professions over the last few weeks. This problem turned up constantly so I either had to /reload or disable GW and use Skillet on the alt till it stopped learning things.