Hello ckoeber:
Unfortunately, there is no way to debug Revit (from the outside, that is) to find out why a particular add-in does not get loaded. You sort of must apply brute-force to figure it out. Sorry 😞 It happens to anyone, occasionally, by the way. I’ve created tons of addins and sometimes I made a mistake that causes them not being loaded. It tends to be something trivial, but I understand when it drives one nuts (as it does for me 🙂
First, try to look for information in the journal file Revit creates. Launch Revit and close it (assuming your command does not show up). There may be some warnings in the journal file possibly explaining the reason. (It depends on the reason, so not always is an info there). I recommend doing this with just that one single addin registered. (So temporarily remove all other *.addin files).
If that does not yield any useful information, follow with brute force. You wrote that other commands work fine. All right, what is different then? Take one addin that works, comment out all of its code (temporarily, of course) and replace it with the code from the command that gives you trouble with loading. Would that work or would it not? If it does, problem is in the addin file. If it does not work, problem is with the code. Maybe you are referring a method somewhere in a referenced DLL that for some reason cannot be loaded. If that is suspected, then start commenting out your command’s code and removing [now] unnecessary references. Assuming all paths and class names are correct, at some point you should reach state when your command is loadable.
By the way: You should not use “ADSK” as your Vendor Id unless you work for us 🙂
(And since you seem to have copy-and-pasted the Vendor Id from another addin, you did not copy the ClientId as well , did you?)
Arnošt Löbel
Sr. Principal Engineer
Autodesk, Revit R&D
Arnošt Löbel
