Server problem while updating and since, no map found

Hi, I own a VIA135, the last time I opened my GPS, May 7, there was no signal. While reading on the TomTom site, I saw that my GPS was touched by the "Week Number Roll-Over". I then updated my GPS, as I do every year. But the update did not complete since there was a servor error. Since that time, every time I open my device, it indicates "map not found". I tried several times to update, but to no avail. I even do a "soft reset", followed by another update, but still the same error since the update is never complete because Mydrive connect freeze at 20%, after 5 minutes freeze, GPS indicate that my GPS can now be disconnected safely. When I restart GPS, it indicates "Map not found". CCleaner and clean C: via Windows has been done.
What to do?