Nuvi 240 LMT maps problem

Hello peepz.

I have a problem with Nuvi 240 LMT with preinstalled Central region Europe maps.

I tried to put some new, different maps, but without success. It always gives me "cannot ulock maps" error, even if i put .unl file in the folder.

I tried to put maps on SD card in Garmin folder, but i'got same error.

Preinstalled map are in hidden folder called . .System (http://prntscr.com/c3ep7w http://prntscr.com/c3epel).

I tried all kind of cures, even to unlock unlocked maps, but nothing :(

Does anybody can help me pls?

Thanks in advance!