This will probably be a useless piece of information, but however.....
When I bought my Mazda 6, the sd card was missing. The dealer allowed me £250 off because of this. So I went on the bay, and found sd cards for sale, around £28. I bought one that was reputedly a dedicated Mazda card for my car, year, type, etc, etc. Card came in 24 hours. Popped it in, only to receive the message..... 'This map cannot be used in this unit...Europe 3117'.
Anyway....after receiving diddly squat response from the seller, I trawled the net, and came across a post with the same problem as me.
The answer was to backup the card first. (just in case I sent it back) Then format it (FAT32) but not Quick format. Then put the card in the NB1 in the car. The unit then downloaded some files onto the card. I then put the card in the card reader back onto this computer. TomTom Home, then fully updated all the files required...took about 20 minutes. I put the card back in the car, and hey ho....we have a fully up to date working NB1 Sat Nav.
I expect it may have done the same using a new card, but not sure.
Possibly useless info, but you never know. Don't know what cars the NB1 is installed in, but if it comes without a card, this is the solution