Navi DVD update GP2

Good morning dear Phaetonists, my P. GP2 (2009) has the DVD V4 as software in the Navi. Now on the market there is already version 7.2, which I bought from VW for 199 €. Unfortunately my RNS 810 strikes again and again when I want to load the DVD “DVD error”. The DVD is flawless, but apparently you need a software update for the RNS so that it can “inhale” the new DVD. Does any of you have any experience with it? I have registered my car in the workshop so that the eventuelists will be able to I update a little. Greeting Thomas