Thank you so much for your patience with me!
I was just disappointed buying from the Marketplace and seeing this product crashing immediately on loading, even in safe mode (meaning, that my community content was already "out" of responsibility). You couldn't help me because of Microsoft's installation procedure responsibility (which I understand because of your explanations above) and Microsoft seemed not to be willing for real support or responsibility than a standard answer (which I had the luck to help me finally). If this answer would not had helped me I fear, that I would have been lost with an useless product for real money and allthough no possibility to claim a refund from Microsoft.
I resume for the future, that it is better to buy directly from the developers than from the marketplace.....
Kind regards
Johannes