and half of the 7 downloads won't even start and say they failed, or they'll download but not open

It continues to say that the zip file is invalid and just will not open!! My connnection is perfectly fine and I've givin it 6 downloads for both cars..
this may or may not be a technical issue on my own and has nothing to do with RRmods, I just really need help.
especially after spending 24 bucks

move if not in right topic, thanks.