Hi Marco,
I am not from Laminar Research; just a flight simmer from downunder.
Your purchase is a third party add-on aircraft which is not sold by Laminar Research (X-plane.com). My assumption is you may have purchased the aircraft from X-Plane.Org. This business has no connection with Laminar Research so you need to deal with the retailer or ultimately with the developer of the addon.
Before you do make that contact consider the following:-
1. Are you trying to install the package as the Administrator?
2. Have you temporarily disabled your antivirus-malware software?
3. Are you running a steam version of X-Plane? If so then you have asked your question in the wrong forum. You need to go to a steam forum. Steam is a third party hybrid, modified version of the official and original version of X-Plane created and developed further by Laminar Research. There is not connection between either parties and the two software packages do not mix and match.
4. On the basis you are using the Laminar version of X-Plane then have a look at the following link by Michael Brown found at https://www.youtube.com/watch?v=V4RjIxrhkXs Michael talks you through the process of installing additional aircraft. Disregard the first part of the video regarding the quality but follow the back-half of the message. Laminar Research recommends Michael's business as the only supplier of PCs suitable for X-Plane.
On the basis that you have not been successful after point 4 then contact your reseller.
Glenn