I get some layout constraints error in iOS - ios

Question

I get some error log info，But the position is not the position code, can you help me to point out the cause of the problem
Below is the details of the crash log, I can't find more position the code, what's the problem.
detail crash log:
The layout constraints still need update after sending -updateConstraints to <_UIKeyboardLayoutAlignmentView: 0x13e6ea660; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x17443ffe0>>.
_UIKeyboardLayoutAlignmentView or one of its superclasses may have overridden -updateConstraints without calling super. Or, something may have dirtied layout constraints in the middle of updating them. Both are programming errors.
(null)
(
0 CoreFoundation 0x0000000185d602f4 <redacted> + 160
1 libobjc.A.dylib 0x000000019758c0e4 objc_exception_throw + 60
2 CoreFoundation 0x0000000185d60218 <redacted> + 0
3 UIKit 0x000000018ae64748 <redacted> + 448
4 UIKit 0x000000018ae64880 <redacted> + 136
5 CoreFoundation 0x0000000185c40cdc CFArrayApplyFunction + 68
6 UIKit 0x000000018ae64620 <redacted> + 152
7 UIKit 0x000000018ae64880 <redacted> + 136
8 CoreFoundation 0x0000000185c40cdc CFArrayApplyFunction + 68
9 UIKit 0x000000018ae64620 <redacted> + 152
10 UIKit 0x000000018ae64880 <redacted> + 136
11 UIKit 0x000000018a89b7b4 <redacted> + 104
12 Foundation 0x0000000186bc1308 <redacted> + 176
13 UIKit 0x000000018a89b4d0 <redacted> + 212
14 UIKit 0x000000018a8b7e04 <redacted> + 104
15 UIKit 0x000000018ae64be4 <redacted> + 180
16 UIKit 0x000000018a7b2140 <redacted> + 588
17 UIKit 0x000000018ac71bd0 <redacted> + 792
18 UIKit 0x000000018aaa8fb0 <redacted> + 1860
19 UIKit 0x000000018a824240 <redacted> + 356
20 UIKit 0x000000018a7946ec <redacted> + 536
21 CoreFoundation 0x0000000185d182a4 <redacted> + 32
22 CoreFoundation 0x0000000185d15230 <redacted> + 360
23 CoreFoundation 0x0000000185d15610 <redacted> + 836
24 CoreFoundation 0x0000000185c412d4 CFRunLoopRunSpecific + 396
25 GraphicsServices 0x000000018f4576fc GSEventRunModal + 168
26 UIKit 0x000000018a806fac UIApplicationMain + 1488
27 Myapp 0x1001803b0 Myapp + 1573808
28 libdyld.dylib 0x0000000197c0aa08 <redacted> + 4
)
dSYM UUID: B1FB72DD-A4D0-3ABA-BF95-9FCD83749770
CPU Type: arm64
Slide Address: 0x0000000100000000
Binary Image: Myapp
Base Address: 0x00000001000f0000

Answer 1

If you implemented updateConstraints you need to call [super updateConstraints]; within your implementation.
See https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIView_Class/index.html#//apple_ref/occ/instm/UIView/updateConstraints
UPDATE:
_UIKeyboardLayoutAlignmentView is an Apple internal keyboard view. Most likely something is crashing while it is presented.
See this Radar (Apple bug report) and these answers for a potential solution.
The bug seems to be iOS 8.3 specific.
https://openradar.appspot.com/20615507
NSInteralInconsistencyException - UIKeyboardLayoutAlignmentView
iOS 8.3 UIAlertController crashes when trying to add a textfield