Fly is Fun restarting from time to time for no reason

[Dutchy]

And then suddenly something changed. But what?
A few months ago Fly is Fun started for no reason to restart from time to time. For instance by turning the device and therefore changing the screen from landscape to portrait (or vice versa) Fly is Fun shuts off and starts again. Which forces to press “I agree”. Not a nice thing to do during a turbulent flight. Same thing when I want to print a track from the logbook on the map. And for worse: after pressing “I agree” the track isn't showing.
Before operation was fine and as expected. The hardware: Asus MemoPad HD7 with Android 4.2.2 running and a 32GB SD-card. May be not state of the art but very suitable.
Reinstalling Fly is Fun from scratch didn't help. Moving the map and elevation data from the SD-card back to the internal storage didn't help either.
Finally restoring the tablet to factory settings and installing Fly is Fun without any change in storage setting, brought use of Fly is Fun back to normal again. Although very little internal storage space is left (leaving ample space on the SD-card).
And now the same show starts all over again with my recently bought smartphone running Android 5.0.2. Before investing a lot of time in reinstalling and adjusting all the apps on my smartphone after a factory reset I would like to know: am I the only one experiencing this? Nothing is to be found about this on the forum (at least by me). And what can be more easily done to resolve this unexpected and very much unwanted behaviour of Fly is Fun without a time consuming factory reset?
Many thanks in advance for a solution.