No unlocked maps were found for this device.

[mdavis84]

I'm trying to install the file North Cumberland OHV / ATV Trails v2.3, TN Map to my Garmin nuvi 2639 with BaseCamp 4.6.2 and I keep getting No unlocked maps were found, I installed the map to my computer from the file, even restarted computer and garmin, still no luck, anyone run into this issue? Running windows 10 pro.

[popej]

Probably your nuvi doesn't support 3-rd party maps.

[Boyd]

You could try Garmin's older Mapsource program: http://www8.garmin.com/support/download_details.jsp?id=209

Before installing, use this free program to prepare your computer: http://www.javawa.nl/gmtk_en.html

New PC? Use JaVaWa GMTK first, then install MapSource
When you use JaVaWa GMTK to transfer maps to a new PC it is higly recommended to do this before installing MapSource.

After installing, Mapsource will access any maps you have already installed in Basecamp. You can then use it to send the map to the Nuvi - see this tutorial: https://www.gpsfiledepot.com/tutorials/how-to-load-maps-on-my-garmin-gps-unit/#mapsource

I don't like Basecamp/MapInstall very much so I can't offer an explanation of the error message you are getting, but I see frequent posts here where people get the same "no unlocked maps" message when attempting to install maps on a variety of devices.

OTOH, Popej may be right about the newer Garmin automotive devices being incompatible. I have seen others suggest this too, and he knows more about Garmin's map format than I ever will.

[Boyd]

By the way, I forgot to mention that you will need to put your Nuvi into Mass Storage mode before you use Mapsource. See these instructions: http://forums.gpsreview.net/discussion/comment/206037/#Comment_206037

For that matter, you might try doing this and then see if it works with Basecamp/MapInstall since some of Garmin's software appears to have issues with USB on Windows 10.