xamarin/Xamarin.Forms

Picker crashing in ios version 9.1 in xamarin forms version 4.1

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#6,946 opened on Jul 22, 2019

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4.1.0e/3 :clock3:help wantedi/regressioniOS 9p/iOS 🍎t/bug :bug:up-for-grabs

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Description

After i ugrade to xamarin version 4.1, picker is crashing in iOS version 9.1. Issue is not reproducible with versions above 9.3.

Steps to Reproduce

  1. Make sure you have Xamarin forms version 4.0 or above
  2. Declare a picker in xaml
  3. Click the picker
  4. App crash

Expected Behavior

  1. App should not crash and the data should be displayed properly.

Actual Behavior

  1. App crash

Basic Information

  • Version with issue: iOS version 9.1
  • Last known good version: xamarin forms version 3.2
  • IDE: Visual Studio
  • Platform Target Frameworks:
    • iOS: 11.1
  • Affected Devices: all iOS devices with 9.1 os version

###Exception trace

`

Unhandled Exception:

System.NullReferenceException: Object reference not set to an instance of an object

at Xamarin.Forms.Platform.iOS.PickerRendererBase1[TControl].OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs1[TElement] e) [0x00198] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x0012a] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Xamarin.Forms.Platform.iOS.IVisualElementRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x00000] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x00014] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.OnChildAdded (Xamarin.Forms.VisualElement view) [0x0003d] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.Load () [0x0001e] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x000de] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Xamarin.Forms.Platform.iOS.IVisualElementRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x00000] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x00014] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.OnChildAdded (Xamarin.Forms.VisualElement view) [0x0003d] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.Load () [0x0001e] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.PageRenderer.ViewDidLoad () [0x0008f] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at (wrapper managed-to-native) ObjCRuntime.Messaging.IntPtr_objc_msgSendSuper(intptr,intptr)

at UIKit.UIViewController.get_View () [0x0002a] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIViewController.g.cs:2983

at Xamarin.Forms.Platform.iOS.PageRenderer.get_NativeView () [0x00008] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.PageRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x0003d] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x00014] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.AddChild (Xamarin.Forms.VisualElement view) [0x00027] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.WillAppear () [0x00043] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.PlatformRenderer.ViewWillAppear (System.Boolean animated) [0x00016] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at (wrapper managed-to-native) ObjCRuntime.Messaging.void_objc_msgSend(intptr,intptr)

at UIKit.UIWindow.MakeKeyAndVisible () [0x00008] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIWindow.g.cs:259

at Xamarin.Forms.Platform.iOS.FormsApplicationDelegate.SetMainPage () [0x0000c] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.FormsApplicationDelegate.FinishedLaunching (UIKit.UIApplication uiApplication, Foundation.NSDictionary launchOptions) [0x00030] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at PickerSample.iOS.AppDelegate.FinishedLaunching (UIKit.UIApplication app, Foundation.NSDictionary options) [0x00013] in /Users/vipin.raj/Projects/PickerSample/PickerSample/PickerSample.iOS/AppDelegate.cs:28

at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)

at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIApplication.cs:79

at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIApplication.cs:63

at PickerSample.iOS.Application.Main (System.String[] args) [0x00001] in /Users/vipin.raj/Projects/PickerSample/PickerSample/PickerSample.iOS/Main.cs:17

2019-07-22 18:53:52.526 PickerSample.iOS[248:16627] Unhandled managed exception:

Object reference not set to an instance of an object (System.NullReferenceException)

at Xamarin.Forms.Platform.iOS.PickerRendererBase1[TControl].OnElementChanged (Xamarin.Forms.Platform.iOS.ElementChangedEventArgs1[TElement] e) [0x00198] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x0012a] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Xamarin.Forms.Platform.iOS.IVisualElementRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x00000] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x00014] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.OnChildAdded (Xamarin.Forms.VisualElement view) [0x0003d] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.Load () [0x0001e] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].SetElement (TElement element) [0x000de] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementRenderer`1[TElement].Xamarin.Forms.Platform.iOS.IVisualElementRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x00000] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x00014] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.OnChildAdded (Xamarin.Forms.VisualElement view) [0x0003d] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.VisualElementPackager.Load () [0x0001e] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.PageRenderer.ViewDidLoad () [0x0008f] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at (wrapper managed-to-native) ObjCRuntime.Messaging.IntPtr_objc_msgSendSuper(intptr,intptr)

at UIKit.UIViewController.get_View () [0x0002a] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIViewController.g.cs:2983

at Xamarin.Forms.Platform.iOS.PageRenderer.get_NativeView () [0x00008] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.PageRenderer.SetElement (Xamarin.Forms.VisualElement element) [0x0003d] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.CreateRenderer (Xamarin.Forms.VisualElement element) [0x00014] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.AddChild (Xamarin.Forms.VisualElement view) [0x00027] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.Platform.WillAppear () [0x00043] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.PlatformRenderer.ViewWillAppear (System.Boolean animated) [0x00016] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at (wrapper managed-to-native) ObjCRuntime.Messaging.void_objc_msgSend(intptr,intptr)

at UIKit.UIWindow.MakeKeyAndVisible () [0x00008] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIWindow.g.cs:259

at Xamarin.Forms.Platform.iOS.FormsApplicationDelegate.SetMainPage () [0x0000c] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at Xamarin.Forms.Platform.iOS.FormsApplicationDelegate.FinishedLaunching (UIKit.UIApplication uiApplication, Foundation.NSDictionary launchOptions) [0x00030] in <0da03a4594684a9bbf17d4a99d39fbc2>:0

at PickerSample.iOS.AppDelegate.FinishedLaunching (UIKit.UIApplication app, Foundation.NSDictionary options) [0x00013] in /Users/vipin.raj/Projects/PickerSample/PickerSample/PickerSample.iOS/AppDelegate.cs:28

at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)

at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) [0x00005] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIApplication.cs:79

at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) [0x0002c] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.2.1.12/src/Xamarin.iOS/UIKit/UIApplication.cs:63

at PickerSample.iOS.Application.Main (System.String[] args) [0x00001] in /Users/vipin.raj/Projects/PickerSample/PickerSample/PickerSample.iOS/Main.cs:17

2019-07-22 18:53:52.527 PickerSample.iOS[248:16627] critical: Stacktrace:

2019-07-22 18:53:52.528 PickerSample.iOS[248:16627] critical:

Native stacktrace:

2019-07-22 18:53:52.538 PickerSample.iOS[248:16627] critical: 0 PickerSample.iOS 0x00000001013ec068 PickerSample.iOS + 20349032

2019-07-22 18:53:52.538 PickerSample.iOS[248:16627] critical: 1 libsystem_platform.dylib 0x0000000197a0194c _sigtramp + 68

2019-07-22 18:53:52.539 PickerSample.iOS[248:16627] critical: 2 libsystem_pthread.dylib 0x0000000197a08ef8 pthread_kill + 112

2019-07-22 18:53:52.539 PickerSample.iOS[248:16627] critical: 3 libsystem_c.dylib 0x00000001978b2b78 abort + 140

2019-07-22 18:53:52.539 PickerSample.iOS[248:16627] critical: 4 PickerSample.iOS 0x0000000101505ec4 xamarin_get_block_descriptor + 8696

2019-07-22 18:53:52.540 PickerSample.iOS[248:16627] critical: 5 PickerSample.iOS 0x000000010142c97c mono_pmip + 226396

2019-07-22 18:53:52.540 PickerSample.iOS[248:16627] critical: 6 PickerSample.iOS 0x00000001013ebcc4 PickerSample.iOS + 20348100

2019-07-22 18:53:52.541 PickerSample.iOS[248:16627] critical: 7 PickerSample.iOS 0x00000001013ea9c4 PickerSample.iOS + 20343236

2019-07-22 18:53:52.541 PickerSample.iOS[248:16627] critical: 8 PickerSample.iOS 0x00000001013e3008 PickerSample.iOS + 20312072

2019-07-22 18:53:52.541 PickerSample.iOS[248:16627] critical: 9 PickerSample.iOS 0x00000001011d3c1c PickerSample.iOS + 18152476

2019-07-22 18:53:52.542 PickerSample.iOS[248:16627] critical: 10 PickerSample.iOS 0x000000010116b684 PickerSample.iOS + 17725060

2019-07-22 18:53:52.542 PickerSample.iOS[248:16627] critical: 11 PickerSample.iOS 0x0000000101169b80 PickerSample.iOS + 17718144

2019-07-22 18:53:52.543 PickerSample.iOS[248:16627] critical: 12 PickerSample.iOS 0x00000001011581d0 PickerSample.iOS + 17646032

2019-07-22 18:53:52.543 PickerSample.iOS[248:16627] critical: 13 PickerSample.iOS 0x0000000101166cf0 PickerSample.iOS + 17706224

2019-07-22 18:53:52.543 PickerSample.iOS[248:16627] critical: 14 PickerSample.iOS 0x0000000101166418 PickerSample.iOS + 17703960

2019-07-22 18:53:52.544 PickerSample.iOS[248:16627] critical: 15 PickerSample.iOS 0x000000010116b484 PickerSample.iOS + 17724548

2019-07-22 18:53:52.544 PickerSample.iOS[248:16627] critical: 16 PickerSample.iOS 0x0000000101169b80 PickerSample.iOS + 17718144

2019-07-22 18:53:52.545 PickerSample.iOS[248:16627] critical: 17 PickerSample.iOS 0x00000001011581d0 PickerSample.iOS + 17646032

2019-07-22 18:53:52.545 PickerSample.iOS[248:16627] critical: 18 PickerSample.iOS 0x0000000101166cf0 PickerSample.iOS + 17706224

2019-07-22 18:53:52.546 PickerSample.iOS[248:16627] critical: 19 PickerSample.iOS 0x0000000101166418 PickerSample.iOS + 17703960

2019-07-22 18:53:52.546 PickerSample.iOS[248:16627] critical: 20 PickerSample.iOS 0x00000001011c852c PickerSample.iOS + 18105644

2019-07-22 18:53:52.546 PickerSample.iOS[248:16627] critical: 21 PickerSample.iOS 0x00000001003898a8 PickerSample.iOS + 3168424

2019-07-22 18:53:52.547 PickerSample.iOS[248:16627] critical: 22 PickerSample.iOS 0x00000001013fb5a8 mono_pmip + 24712

2019-07-22 18:53:52.548 PickerSample.iOS[248:16627] critical: 23 PickerSample.iOS 0x0000000101468c48 mono_pmip + 472872

2019-07-22 18:53:52.548 PickerSample.iOS[248:16627] critical: 24 PickerSample.iOS 0x000000010146c26c mono_pmip + 486732

2019-07-22 18:53:52.549 PickerSample.iOS[248:16627] critical: 25 PickerSample.iOS 0x0000000100088618 PickerSample.iOS + 17944

2019-07-22 18:53:52.549 PickerSample.iOS[248:16627] critical: 26 PickerSample.iOS 0x00000001000aa1fc PickerSample.iOS + 156156

2019-07-22 18:53:52.550 PickerSample.iOS[248:16627] critical: 27 UIKit 0x00000001879b4098 + 996

2019-07-22 18:53:52.551 PickerSample.iOS[248:16627] critical: 28 UIKit 0x00000001879b3c9c + 28

2019-07-22 18:53:52.551 PickerSample.iOS[248:16627] critical: 29 PickerSample.iOS 0x0000000100ba9ec8 PickerSample.iOS + 11689672

2019-07-22 18:53:52.551 PickerSample.iOS[248:16627] critical: 30 PickerSample.iOS 0x0000000100b61a04 PickerSample.iOS + 11393540

2019-07-22 18:53:52.552 PickerSample.iOS[248:16627] critical: 31 PickerSample.iOS 0x00000001011c6968 PickerSample.iOS + 18098536

2019-07-22 18:53:52.552 PickerSample.iOS[248:16627] critical: 32 PickerSample.iOS 0x00000001011c6c68 PickerSample.iOS + 18099304

2019-07-22 18:53:52.553 PickerSample.iOS[248:16627] critical: 33 PickerSample.iOS 0x00000001011581d0 PickerSample.iOS + 17646032

2019-07-22 18:53:52.553 PickerSample.iOS[248:16627] critical: 34 PickerSample.iOS 0x00000001011597b8 PickerSample.iOS + 17651640

2019-07-22 18:53:52.553 PickerSample.iOS[248:16627] critical: 35 PickerSample.iOS 0x0000000101159514 PickerSample.iOS + 17650964

2019-07-22 18:53:52.554 PickerSample.iOS[248:16627] critical: 36 PickerSample.iOS 0x000000010115eb44 PickerSample.iOS + 17673028

2019-07-22 18:53:52.554 PickerSample.iOS[248:16627] critical: 37 PickerSample.iOS 0x00000001003898a8 PickerSample.iOS + 3168424

2019-07-22 18:53:52.555 PickerSample.iOS[248:16627] critical: 38 PickerSample.iOS 0x00000001013fb5a8 mono_pmip + 24712

2019-07-22 18:53:52.555 PickerSample.iOS[248:16627] critical: 39 PickerSample.iOS 0x0000000101468c48 mono_pmip + 472872

2019-07-22 18:53:52.556 PickerSample.iOS[248:16627] critical: 40 PickerSample.iOS 0x000000010146c26c mono_pmip + 486732

2019-07-22 18:53:52.556 PickerSample.iOS[248:16627] critical: 41 PickerSample.iOS 0x000000010009aa80 PickerSample.iOS + 92800

2019-07-22 18:53:52.557 PickerSample.iOS[248:16627] critical: 42 PickerSample.iOS 0x000000010009ab44 PickerSample.iOS + 92996

2019-07-22 18:53:52.557 PickerSample.iOS[248:16627] critical: 43 UIKit 0x00000001879cc5f4 + 628

2019-07-22 18:53:52.558 PickerSample.iOS[248:16627] critical: 44 UIKit 0x00000001879cc368 + 156

2019-07-22 18:53:52.558 PickerSample.iOS[248:16627] critical: 45 UIKit 0x00000001879bc324 + 596

2019-07-22 18:53:52.558 PickerSample.iOS[248:16627] critical: 46 UIKit 0x00000001879bb5cc + 448

2019-07-22 18:53:52.559 PickerSample.iOS[248:16627] critical: 47 UIKit 0x00000001879bac84 + 664

2019-07-22 18:53:52.559 PickerSample.iOS[248:16627] critical: 48 UIKit 0x00000001879b7f78 + 252

2019-07-22 18:53:52.560 PickerSample.iOS[248:16627] critical: 49 UIKit 0x0000000187a2d8f0 + 48

2019-07-22 18:53:52.560 PickerSample.iOS[248:16627] critical: 50 PickerSample.iOS 0x0000000100bac068 PickerSample.iOS + 11698280

2019-07-22 18:53:52.560 PickerSample.iOS[248:16627] critical: 51 PickerSample.iOS 0x0000000100b622f8 PickerSample.iOS + 11395832

2019-07-22 18:53:52.561 PickerSample.iOS[248:16627] critical: 52 PickerSample.iOS 0x0000000101156580 PickerSample.iOS + 17638784

2019-07-22 18:53:52.561 PickerSample.iOS[248:16627] critical: 53 PickerSample.iOS 0x0000000101155368 PickerSample.iOS + 17634152

2019-07-22 18:53:52.562 PickerSample.iOS[248:16627] critical: 54 PickerSample.iOS 0x00000001000b8a4c PickerSample.iOS + 215628

2019-07-22 18:53:52.562 PickerSample.iOS[248:16627] critical: 55 PickerSample.iOS 0x00000001003898a8 PickerSample.iOS + 3168424

2019-07-22 18:53:52.563 PickerSample.iOS[248:16627] critical: 56 PickerSample.iOS 0x00000001013fb5a8 mono_pmip + 24712

2019-07-22 18:53:52.563 PickerSample.iOS[248:16627] critical: 57 PickerSample.iOS 0x0000000101468c48 mono_pmip + 472872

2019-07-22 18:53:52.564 PickerSample.iOS[248:16627] critical: 58 PickerSample.iOS 0x000000010146c26c mono_pmip + 486732

2019-07-22 18:53:52.564 PickerSample.iOS[248:16627] critical: 59 PickerSample.iOS 0x000000010008a8b0 PickerSample.iOS + 26800

2019-07-22 18:53:52.565 PickerSample.iOS[248:16627] critical: 60 PickerSample.iOS 0x000000010008af1c PickerSample.iOS + 28444

2019-07-22 18:53:52.565 PickerSample.iOS[248:16627] critical: 61 UIKit 0x0000000187a29324 + 400

2019-07-22 18:53:52.565 PickerSample.iOS[248:16627] critical: 62 UIKit 0x0000000187c57acc + 2904

2019-07-22 18:53:52.566 PickerSample.iOS[248:16627] critical: 63 UIKit 0x0000000187c5be0c + 1656

2019-07-22 18:53:52.567 PickerSample.iOS[248:16627] critical: 64 UIKit 0x0000000187c58f50 + 168

2019-07-22 18:53:52.567 PickerSample.iOS[248:16627] critical: 65 FrontBoardServices 0x000000018c23f7c4 + 184

2019-07-22 18:53:52.567 PickerSample.iOS[248:16627] critical: 66 FrontBoardServices 0x000000018c23fb44 + 56

2019-07-22 18:53:52.568 PickerSample.iOS[248:16627] critical: 67 CoreFoundation 0x00000001823d8544 + 24

2019-07-22 18:53:52.568 PickerSample.iOS[248:16627] critical: 68 CoreFoundation 0x00000001823d7fd8 + 540

2019-07-22 18:53:52.569 PickerSample.iOS[248:16627] critical: 69 CoreFoundation 0x00000001823d5cd8 + 724

2019-07-22 18:53:52.569 PickerSample.iOS[248:16627] critical: 70 CoreFoundation 0x0000000182304ca0 CFRunLoopRunSpecific + 384

2019-07-22 18:53:52.570 PickerSample.iOS[248:16627] critical: 71 UIKit 0x0000000187a221c8 + 460

2019-07-22 18:53:52.570 PickerSample.iOS[248:16627] critical: 72 UIKit 0x0000000187a1cffc UIApplicationMain + 204

2019-07-22 18:53:52.571 PickerSample.iOS[248:16627] critical: 73 PickerSample.iOS 0x0000000100bb7d78 PickerSample.iOS + 11746680

2019-07-22 18:53:52.571 PickerSample.iOS[248:16627] critical: 74 PickerSample.iOS 0x0000000100b4070c PickerSample.iOS + 11257612

2019-07-22 18:53:52.572 PickerSample.iOS[248:16627] critical: 75 PickerSample.iOS 0x0000000100b406cc PickerSample.iOS + 11257548

2019-07-22 18:53:52.573 PickerSample.iOS[248:16627] critical: 76 PickerSample.iOS 0x00000001000b8890 PickerSample.iOS + 215184

2019-07-22 18:53:52.573 PickerSample.iOS[248:16627] critical: 77 PickerSample.iOS 0x00000001003898a8 PickerSample.iOS + 3168424

2019-07-22 18:53:52.574 PickerSample.iOS[248:16627] critical: 78 PickerSample.iOS 0x00000001013fb5a8 mono_pmip + 24712

2019-07-22 18:53:52.574 PickerSample.iOS[248:16627] critical: 79 PickerSample.iOS 0x0000000101468c48 mono_pmip + 472872

2019-07-22 18:53:52.575 PickerSample.iOS[248:16627] critical: 80 PickerSample.iOS 0x000000010146df04 mono_pmip + 494052

2019-07-22 18:53:52.576 PickerSample.iOS[248:16627] critical: 81 PickerSample.iOS 0x00000001013e23b0 PickerSample.iOS + 20308912

2019-07-22 18:53:52.576 PickerSample.iOS[248:16627] critical: 82 PickerSample.iOS 0x0000000101514404 _Z9__isctypeim + 47160

2019-07-22 18:53:52.576 PickerSample.iOS[248:16627] critical: 83 PickerSample.iOS 0x00000001000b4ff4 PickerSample.iOS + 200692

2019-07-22 18:53:52.577 PickerSample.iOS[248:16627] critical: 84 libdyld.dylib 0x00000001978228b8 + 4

2019-07-22 18:53:52.577 PickerSample.iOS[248:16627] critical:

=================================================================

Got a SIGABRT while executing native code. This usually indicates

a fatal error in the mono runtime or one of the native libraries

used by your application.

=================================================================

Contributor guide

Research direction
Investigate the null reference exception in PickerRendererBase.OnElementChanged on iOS 9.1. Check for API differences or missing null checks in the renderer for that iOS version.
Tech stack
csharp
Domain
mobile
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
Xamarin.FormsiOS developmentVisual Studio
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75