sorry I’m not sure what you mean… I have a feeling we’re talking about different things.
When the World Update of Spain was released, we had to “purchase” it in the Marketplace. For free of course, but the process is the same. This very process, the blue buy and install button was greyed out and on the left side just below the title of the update I was told in small red letters that there were prerequisites to install the updates. Below that was the list of some of the default aircraft I had uninstalled, not all for some reasons. I frowned and went to the content manager, installed them and then I could download the World Update.
When Italy came out the same thing happened again, this time it was the Pitts and the Hornet which had still been missing.
I am aware that the topic has been solved and I think this is really material for another topic. I just wanted to explain the situation. =)