Cannot Unlock Maps - Garmin Nuvi

Why can’t you go through the steps I’ve outlined ON THE DEVICE and unconnected to your PC and write down the list of maps on the device?

Here goes. Folders listed on Internal Storage on Garmin Nuvi58: Demo, Garmin, GPX, HELP, Keyboards, Map, POI, Text, Themes, Vehicle and Voice. I just reinstalled City Navigator UK & Ireland 2025.20. using Garmin Express. Garmin Express says "you're up to date!".  Map folder is empty. Garmin folder has what looks like a Bing link which says GarminDevice.xml. If I click on that link it takes me to C:/Users/wingreen/AppData/Local/Microsoft/Windows/INetCache/IE/L89CAHT4/GarminDevice[1].xml. (My C drive doesnt have that folder link). On the page it takes me to it is headed "This XML file does not appear to have any style information associated with it. The document tree is shown below". Listed on the page is lots and lots of text, which the system wont let me post here - but looks like computer instructions

That isn't what is being asked. Use the menus on your device. Select Settings then Map then Map Info, what is listed there?

Oops. Sorry. Under Settings,  Map & Vehicle, my Maps is a 'page headed Update Maps and on there it reads CN Europe NTU 2025.20 Foursquare. There is an orange tick in the box next to it..

When I turn the Nuvi58 on it says Detailed Maps required for routing. No detailed Maps found on this device. Screen then changes to say Cannot Unlock Maps.

The foursquare map is simply a poi database. Something is really strange here, would be worth you trying the clone method mentioned here www.poi-factory.com/.../39231

@SUSSAMB, what are your thoughts about the memory card the individual is using?  Early on he has stated "I have over 5Gb available.".

Thanks again. It looks a bit scary but I might give it a go. Garmin themselves not very helpful. I'm now actually considering downloading and installing one of the free .img  files available and making do with that.....won't have all the bells and whistles of the proper Garmin one, but might be my only option.

Think he was referring to his device rather than a card?

At various times he has stated the following:

"I've never had to use an SD card....routes were on internal memory....and there are plenty of GBs on there."  [stated early in the thread]

"The SD card (and internal 7Gb - I tried both) should be big enough."  [In sequence after the above statement]

But I think the nuvi 58 comes with 8 GB so he may only have 1 GB left.  He has further stated the SD card has 5GB which really isn't enough to reliably install a map update these days. 

If that was my unit I would buy a 32GB card, make sure it is formatted FAT 32, install and retest.