276C database error message in 'message / log' screen

Experienced 276C user here. Had to re-boot my 276C. Running City Navigator 2015 NT 2015.10; same software as before. Waypoints and routes re-loaded easily. Selected map set captured and reloaded (apparently) correctly over nine minutes. All good so far. However, selected maps do not show in the Map Information screen, and are not available to the unit.
Database Error shows in the Message / Log screen.
Must be missing something simple, but your suggestions will be appreciated. Thank you,
Jason

 

Can't say. Unit would not boot, so did a master reset. City Navigator 2015 remains installed, but transferred state maps kind of 'disappear' into the 276C and are not visible or available. I appreciate you assistance!

 

Thanks NUV-Nebie. All is stock Garmin. Map space on the unit is fully open. Two hours with three folks at Garmin led no-where BUT, have found that maps are being imported but cannot be opened. Strange, since nothing has been changed. Working on that angle now. Glitch may be that me maps (2015) are now non-current, and will no re-load.