So to save someone else from wasting a lot of time digging into it, this is an explanation of the root cause as I understand it, so anyone can apply their own solution to their particular situation.
If you aren't using the specific mod manager they use, you are out of luck understanding how to apply their lesson to your situation without a lot of research and experimentation. I've found more than a dozen attempts over the years to explain how to resolve this, but none of them explain exactly what this error means. MCM warning message: 'DarNified UI has been detected in the HUD but not the Start Menu.'
