I put out an update of one of my apps less than two weeks ago on June 25, and it works fine on iOS 9 devices. Starting a few days ago, new iOS builds crash on launch when run on iOS 9 devices. Trial and error turned up that the problem is plugin.fbAudienceNetwork.paid.
When I check the crash log on device, I see this error:
library not loaded @rpath/libswiftcore.dylib
Which makes me think it’s related to Facebook using Swift in their SDK, as @vlads mentions here.
Is there a solution to this problem? At present, it looks like I’m faced with the choice of not running FB ads on iOS devices, or cutting support for iOS 9.