nuvi 14xx root should be like this one:
Bring nuvi12xx_13xx_14xxKeyboards_320.rgn to computer where your device is attached.Code:Please Login or Register to see the links
Then you can drag-and-drop nuvi12xx_13xx_14xxKeyboards_320.rgn onto the WebUpdater icon on your desktop.
Try to clean Vehicle folder, backup first your files on Mac and run again Webupdater or Express.
Bookmarks