I tested app on 10 different iOS devices, with and without Internet connection, with direct build and with Testflight build - app works. I tried different language settings, different regional settings - it works.
When I submit it for review it gets rejected for reason "Performance - 2.1" - app crash for them on first view.
Here is crash log Apple review team sent:
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000001, 0x00000001000a5d6c
Triggered by Thread: 0
Filtered syslog:
None found
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 App name 0x00000001000a5d6c 0x100050000 + 351596
1 App name 0x00000001000a2dac 0x100050000 + 339372
2 UIKit 0x00000001882f0be8 -[UIApplication sendAction:to:from:forEvent:] + 100
3 UIKit 0x00000001882f0b64 -[UIControl sendAction:to:forEvent:] + 80
4 UIKit 0x00000001882d8870 -[UIControl _sendActionsForEvents:withEvent:] + 436
5 UIKit 0x00000001882f0454 -[UIControl touchesEnded:withEvent:] + 572
6 UIKit 0x00000001882f0084 -[UIWindow _sendTouchesForEvent:] + 804
7 UIKit 0x00000001882e8c20 -[UIWindow sendEvent:] + 784
8 UIKit 0x00000001882b904c -[UIApplication sendEvent:] + 248
9 UIKit 0x00000001882b7628 _UIApplicationHandleEventQueue + 6568
10 CoreFoundation 0x000000018311909c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 24
11 CoreFoundation 0x0000000183118b30 __CFRunLoopDoSources0 + 540
12 CoreFoundation 0x0000000183116830 __CFRunLoopRun + 724
13 CoreFoundation 0x0000000183040c50 CFRunLoopRunSpecific + 384
14 GraphicsServices 0x0000000184928088 GSEventRunModal + 180
15 UIKit 0x0000000188322088 UIApplicationMain + 204
16 App name 0x0000000100086d1c 0x100050000 + 224540
17 libdyld.dylib 0x0000000182bde8b8 start + 4
Whatever I try (as described at top of question) I can't make app crash. I really can't figure out what is different in settings that they use on their test devices and in settings on devices I use for test (please note again: I'm not testing on one or two - I tested on 10 devices). I also tried on several last versions of iOS and (of course) on version 9.3.3 they use for test - it works.
I would really appreciate some advice regarding crash log here or how to make some configuration to make this app crash (so I can debug it).