ALCON:
from DJI's forum:
--- snip ---
Dear users,
Please note that there are some compatibility issues between the newly-released iOS 11.2.5 and our DJI GO 3.1.24, 3.1.26 or DJI GO 4 4.2.4 apps. The drone platforms potentially affected by this update are the Phantom 3 series, Phantom 4 series...