So I was able to get my dropAssistant to be called by including my Navigator content within the project explorer view. While this works, it is not the way I would want it to work since it adds my navigator content to the project explorer view which doesn't make sense.

I beleive the problem lies in how the drag enter validate drop works. The drag enter if it runs into a local selection transfer will use that. However, later on the validate drop won't know what to do with the selection an thus ignore it. It it had instead used the plugin drop everything would have been fine.

I'm not sure why this does not make sense to you. You are essentially modifying the Project Explorer to handle the drop of your object then your plugin is installed. I think this is the way things are supposed to work.

Can you elaborate on the last sentence please? (Forgive me, I have been away from this code for a while, but I would like to understand if we need to do anything here).