Reproduction steps:
1. Open the attached Xcode project (02/20/2018).
2. Build it to iOS.

Actual result:
- The application will crash:
* thread #1, stop reason = EXC_BREAKPOINT (code=1, subcode=0x120049088)
* frame #0: 0x0000000120049088 dyld`dyld_fatal_error
frame #1: 0x000000012004befc dyld`dyld::halt(char const*) + 96
frame #2: 0x000000012004e1b8 dyld`dyld::_main(macho_header const*, unsigned long, int, char const**, char const**, char const**, unsigned long*) + 3920
frame #3: 0x0000000120049044 dyld`_dyld_start + 68

Reproduced with:
iPhone SE iOS 9.3
iPhone 6+ iOS 8.0

Not reproducible with:
iPod Touch 6th gen iOS 10.2
iPhone 7 iOS 11.0
iPad Mini 3 iOS 10.3

Note:
- Full Unity project is attached in the OC link (03/01/2018):
= Make sure libraries are included in Xcode Build Phases: ImageIO.framework and UserNotifications.framework.

Resolved (by design): old iOS devices crashed because UserNotifications.framework requires at least iOS 10.0