Fatal update
This update has a bug fatal to all your waypoints and routes, or any other information stored on the app, if you use "a lot" of map tiles.
So says Garmin after the fact. Of course its Apples fault, and it may well be, but some simple testing before sending out the update would have disclosed the problem.
Sadly, this might be your first notice of the problem. But dont worry, Garmin is working on it.
Fshhfdsdh about
Garmin BlueChart® Mobile