My success :

I downloaded a 960 skandinavia map for my tomtom start, I found the latest F/A here and went on with it. I used new files and replaced those in map folder on device. I did some tries with F/A but didnt get it to work.
I did many different variations and in the end I gave up thinking my map package could be faulty.
I downloaded latest map with meta from here and placed that new folder in root of my tomtom start and also added the speedcam files and extras that was in old map folder.
Then I started F/A and ran options 1 to 4 , in that order and tried via the TomTom HOME , if I could select successfully the new map folder. And yes , it worked now.
Disconnected and tried directly on device, also success.

It also says in TomTom HOME that my maps are updated.

I do have two identical map names in my list of maps , I guess I could fix that easily by just deleting the old map.