我在iOS9的生产环境中经常遇到崩溃。它曾经在iOS8中正常工作。我相信这是与键盘相关的，在日志中，每次崩溃都发生在应用程序进入后台之后。但我无法重现。任何帮助表示赞赏。
{
"StackTrace" : [
"#0 CoreFoundation 0X00000001854C4F48 <redacted>()",
"#1 libobjc.A.dylib 0X000000019A013F80 objc_exception_throw()",
"#2 CoreFoundation 0X00000001854CBC5C <redacted>()",
"#3 CoreFoundation 0X00000001854C8C00 <redacted>()",
"#4 CoreFoundation 0X00000001853CCCAC -[NSKVONotifying__UIPopoverLayoutInfo setContentInset:]",
"#5 UIKit 0X000000018AF5D7E0 -[_UIKeyboardTextSelectionGestureController redisableEnclosingScrollViewNestedPinching]",
"#6 UIKit 0X000000018AF5C640 -[_UIKeyboardTextSelectionGestureController _cleanupDeadGesturesIfNecessary]",
"#7 UIKit 0X000000018AF60C58 -[_UIKeyboardBasedTextSelectionGestureController _cleanupDeadGesturesIfNecessary]",
"#8 UIKit 0X000000018AE64734 -[UIKeyboardImpl setTextSelectionControllerFromDelegate]",
"#9 UIKit 0X000000018AA85800 -[UIKeyboardImpl setDelegate:force:]",
"#10 UIKit 0X000000018AA7F0B8 -[UIPeripheralHost _reloadInputViewsForResponder:]",
"#11 UIKit 0X000000018AB68BB4 -[UIResponder _finishResignFirstResponder]",
"#12 UIKit 0X000000018AB09FD4 -[UIResponder resignFirstResponder]",
"#13 UIKit 0X000000018AC7B72C -[UIWebDocumentView resignFirstResponder]",
"#14 UIKit 0X000000018AC7B648 -[UIWebBrowserView resignFirstResponder]",
"#15 UIKit 0X000000018B14E2E8 -[_UIRemoteKeyboards keyboardChanged:shouldConsiderSnapshottingKeyboard:isLocalEvent:]",
"#16 UIKit 0X000000018B14E52C <redacted>()",
"#17 FrontBoardServices 0X000000018F10F7C4 -[FBSSerialQueue _performNext]",
"#18 FrontBoardServices 0X000000018F0F5D4C -[FBSWorkspace synchronizeSystemAnimationFencesWithSpinCleanUpBlock:]",
"#19 UIKit 0X000000018ACFC430 -[UIApplication _synchronizeSystemAnimationFencesWithSpinCleanUpBlock:]",
"#20 UIKit 0X000000018AD4EF84 <redacted>()",
"#21 QuartzCore 0X000000018A287B28 <redacted>()",
"#22 QuartzCore 0X000000018A24CDC4 <redacted>()",
"#23 QuartzCore 0X000000018A24CA08 <redacted>()",
"#24 MediaToolbox 0X0000000187DEACB4 <redacted>()",
"#25 libdispatch.dylib 0X000000019A82BDD4 dispatch_mig_server()",
"#26 libdispatch.dylib 0X000000019A8256A8 <redacted>()",
"#27 libdispatch.dylib 0X000000019A83C2BC <redacted>()",
"#28 libdispatch.dylib 0X000000019A827B9C <redacted>()",
"#29 libdispatch.dylib 0X000000019A82A868 _dispatch_main_queue_callback_4CF()",
"#30 CoreFoundation 0X000000018547C1F8 <redacted>()",
"#31 CoreFoundation 0X000000018547A060 <redacted>()",
"#32 CoreFoundation 0X00000001853A8CA0 CFRunLoopRunSpecific()",
"#33 GraphicsServices 0X0000000190410088 GSEventRunModal()",
"#34 UIKit 0X000000018AAC0FFC UIApplicationMain()",
"#35 Ambulatory 0X00000001000B62B4 -[AppDelegate openChartSummaryAfterLoginWithPatient:andEncounter:]",
"#36 libdyld.dylib 0X000000019A8568B8 <redacted>()"
]
}