@Boki_Srb, thanks for responding. I deleted the "data" and "addons" lines along with the duplicates, but Nextgen still crashes when trying to save a user poi.
I've also noticed that Nextgen crashes when I select the "Favorites" icon (star symbol). In the past, iGO use to save such information to a user profile folder, but it seems that Nextgen does not use one. I've also noticed a Youtube video ([Only registered and activated users can see links. Click Here To Register...]) where a person is unable to save Favorites, History and settings on his car system. I wonder if the problem is related. I've searched elsewhere in this forum, but am unable to find any references to saving user data, pois.