Dear all,
I have been a keen user to this forum and I know brainpower is abundat here, so I am hoping to get some help...
My Nuvi 67 has worked fine since 2016 when I unlocked it, and I have had several maps installed via SD card os .System directory and unlocked using gimunlock . I had a perfectly working EUROPE map installed, 3.85Gb on SD card. I cut It and copied to my computer just to make room for a new North America map and have a backup.
I unlocked the NA map, installed, did not work, tried gimunlock both in SD card directly and in computer folder prior to copy. Then I copied my Europe map again, and surprisingly it did not work as well. At this point no new maps that I add work and I always get the same message, Corrupted map, and so on.

Anyone can explain me what did I do wrong?

Garmin Express most probably updated your Firmware the last update was October 2, 2017, your device requires patching again to be able to use unlocked maps. Confirm your HWID first
<PartNumber>006-B2088-00</PartNumber>
<SoftwareVersion>460</SoftwareVersion>
<Description>nuvi 67</Description>

software/universal-firmware-patcher-for-protected-garmin-devices-t17987-615.html?hilit=MapInstall%20v4.2.4#p180110