eastern europe garmin edge 540

Good morning, I have an issue when I try to install eastern europe maps:
it is selectable, but when selected - button "apply changes" is going disabled..

I use latest garmin express application on mac os.
my device (edge 540) is auto updated so I assume it have latest version.
I need map of Poland - for now I'm stuck...

Please help,

Regards,

Maciej