Martial, contact their support. Support is provided by Bentley Software. You can use this link on e-on software's site:

https://info.e-onsoftware.com/support?hsCtaTracking=15741fb1-4694-44ae-b37d-7a6f9cd72b01%7C309f1699-5a3e-47f5-9791-d35260469946

to describe your problem. I had similar problems with licence keys not working and having 0 days on my paid-for versions of Vue, and their support was pretty good, but you do need to describe the issue in detail. They did get back to me pretty quickly on most the issues I raised, and apart from the graphics card issue, the problems were all satisfactorily resolved. If you didn't receive a licence key for the trial version you probably need one, and they have forgotten to send it. If you did get one, it may be out of date or the wrong one for your version, so get onto them and they will give you some help.