I've been trying to grab some facts left and right on the forum and I have succeeded in making a relatively small 600MB map but is seems that I'm doing something wrong because when I want to navigate to a city it insists on asking me to input a province. Which it chooses not to recognise...

Please follow my steps and tell me what I am doing wrong.
I started out with the downloaded .img of CN Europe NTU 2015.10 West & Central_Unlocked.

Using GMapTool I've split the map into 296 .img files, and one file of the following types: .TRF, TYP and a MPS file.
Then, I've been joining all image files containing Belgium, Netherlands, Luxemburg and Germany.
Producing a gmapsupp.img which I then put this on a sd card in a Garmin directory.

It looked like it's working but it keeps on asking for the province when I want to input a city and an address.
I've been adding and deleting the .TRF, .TYP and .MPS file but that hasn't made a difference that I noted.

Am I doing something basically wrong, am I using the wrong program or an incorrect base file?
Or is the 200 too old a device with its 500 MB internal memory and a sd card?
Your comments, please. Thanks !