After updating to FW version 24.19 from the version before 24.18 I discovered that I could not see any map details on my map data field. I tried to manage my maps in Garmin Express but during installing the maps I wanted I got an error message that the installing process (at 50%) was not allowed to remove a map (the old one?) because it was locked. What is going on? If I have to remove the locked map first to complete the installing process of the maps how do I unlock the (existing?) map first? Any help is appreciated.