[Solved] Addictive Drums Unauthorized After X3e Install
I figured out the solution before I posted the thread asking the question, but thought others might find this helpful.
When I installed X3e on my laptop Windows suggested compatibility mode and chose Vista, for reasons only Microsoft understands. So I right-clicked on the EXE properties and changed compatibility mode to Windows 7.
However, it turns out compatibility mode generates a new computer ID as far as Addictive Drums is concerned, so you're no longer authorized.
It took me a couple hours - removing registered computer, adding new computer, trying to re-register, not being allowed to, etc. until I saw someone in the XLN forums had a similar problem with a different program. The solution: uncheck compatibility mode, the computer ID returns to normal, and everything becomes authorized again.