I get the same error and various zip programs say it's a corrupted file.
Before, I came to this forum; I just went through a lot of nonsense with the online "support" people -- specifically "Yolanda P". I specifically informed them of the "invalid file" error and they wanted to delete my maps off the Rider2. I insisted that I wasn't going to delete them and kill my only working maps. They wanted me to uninstall/install the TomTom Home program after I told them 3 times that it was not working on *2* computers that were BOTH new installs of Home. They wanted me to check my device for errors. The problem is not with my device. It is with their file(s) and they won't listen. They tried to tell me the zip file couldn't be opened outside of Home because it's a different format. At one point, they said the file was corrupted because of the internet connection; but if I delete my maps off the device and update AGAIN, it will work. Huh??? If I can't get a good map, how is getting another map going to get me a good map after I delete my only good map? They tried to send me directions to scan my device and pasted an article with invalid links to instructions to scan your device.
Even much of the TomTom support site doesn't work properly. I didn't even want to chat with someone because they always irritate me. I simply wanted to submit the email and go about my business instead of wasting my time. It wouldn't submit an "Email Us" request without going to the chat request and if you cancel the chat request, the email never submits.
I am a computer technician and I hate it when people that are working for tech support spout nonsense they no nothing about. They won't listen. I just gave up on them. I am agitated because "tech support" usually is not.