The error and empty pages within the UI Kit are throwing error when you PopAsync the page. You have to open the page and close it twice to receive the error. The error is
"**System.ObjectDisposedException:** 'Cannot access a disposed object.
Object name: 'SfGradientViewRenderer'.'
2019-08-27 20:53:02.800501-0500 Angelia.iOS[62106:2044906] [AppCenterCrashes] ERROR: +[MSWrapperLogger MSWrapperLog:tag:level:]/7 Unhandled Exception:
System.ObjectDisposedException: Cannot access a disposed object.
Object name: 'SfGradientViewRenderer'.
at Foundation.NSObject.get_SuperHandle () [0x00012] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.14.0.110/src/Xamarin.iOS/Foundation/NSObject2.cs:449
at UIKit.UIView.SetNeedsDisplay () [0x00023] in /Library/Frameworks/Xamarin.iOS.framework/Versions/12.14.0.110/src/Xamarin.iOS/UIKit/UIView.g.cs:1742
at Syncfusion.XForms.iOS.Graphics.SfGradientViewRenderer.BackgroundBrush_PropertyChanged (System.Object sender, System.ComponentModel.PropertyChangedEventArgs e) [0x00099] in <86b537a434ec42f1a3ba9b5a68a32872>:0
at (wrapper delegate-invoke) <Module>.invoke_void_object_PropertyChangedEventArgs(object,System.ComponentModel.PropertyChangedEventArgs)
at Xamarin.Forms.BindableObject.OnPropertyChanged (System.String propertyName) [0x00000] in D:\
a\1\s\Xamarin.Forms.Core\BindableObject.cs:211
at Xamarin.Forms.Element.OnPropertyChanged (System.String propertyName) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:359
at Xamarin.Forms.Element.set_Parent (Xamarin.Forms.Element value) [0x000e9] in D:\a\1\s\Xamarin.Forms.Core\Element.cs:216
at Syncfusion.XForms.Graphics.SfGradientView.BackgroundBrushPropertyChanged (Syncfusion.XForms.Graphics.SfGradientBrush oldValue, Syncfusion.XForms.Graphics.SfGradientBrush newValue) [0x0000d] in <94efb3866b9846b59125ec72ee515a96>:0
at Syncfusion.XForms.Graphics.SfGradientView.OnBackgroundBrushPropertyChanged (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue) [0x00000] in <94efb3866b9846b59125ec72ee515a96>:0
at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.
Boolean silent) [0x00120] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:445
at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x00173] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:379
at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.Boolean checkAccess) [0x00042] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:316
at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:293
at Syncfusion.XForms.Graphics.SfGradientView.set_BackgroundBrush (Syncfusion.XForms.Graphics.SfGradientBrush value) [0x00000] in <94efb3866b9846b59125ec72ee515a96>:0
at Syncfusion.XForms.Buttons.SfButton.OnGradientColorPropertyChanged () [0x00014] in <
450e40dcb33442d298a31fa64d283d2e>:0
at Syncfusion.XForms.Buttons.SfButton.OnGradientColorPropertyChanged (Xamarin.Forms.BindableObject bindable, System.Object oldValue, System.Object newValue) [0x0000a] in <450e40dcb33442d298a31fa64d283d2e>:0
at Xamarin.Forms.BindableObject.SetValueActual (Xamarin.Forms.BindableProperty property, Xamarin.Forms.BindableObject+BindablePropertyContext context, System.Object value, System.Boolean currentlyApplying, Xamarin.Forms.Internals.SetValueFlags attributes, System.Boolean silent) [0x00120] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:445
at Xamarin.Forms.BindableObject.SetValueCore (Xamarin.Forms.BindableProperty property, System.Object value, Xamarin.Forms.Internals.SetValueFlags attributes, Xamarin.Forms.BindableObject+SetValuePrivateFlags privateAttributes) [0x00173] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:379
at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle, System.
Boolean checkAccess) [0x00042] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:316
at Xamarin.Forms.BindableObject.SetValue (Xamarin.Forms.BindableProperty property, System.Object value, System.Boolean fromStyle) [0x00000] in D:\a\1\s\Xamarin.Forms.Core\BindableObject.cs:303
at Xamarin.Forms.Setter.Apply (Xamarin.Forms.BindableObject target, System.Boolean fromStyle) [0x000ba] in D:\a\1\s\Xamarin.Forms.Core\Setter.cs:75
at Xamarin.Forms.VisualStateManager.GoToState (Xamarin.Forms.VisualElement visualElement, System.String name) [0x000be] in D:\a\1\s\Xamarin.Forms.Core\VisualStateManager.cs:88
at Syncfusion.XForms.iOS.Buttons.NativeTouchEffect.ChangeVisualState (System.String state) [0x00000] in <cf0a6fe010b14eed82a0909e12ee6695>:0
at Syncfusion.XForms.iOS.Buttons.NativeTouchEffect.TouchesBegan (Foundation.NSSet touches, UIKit.UIEvent evt) [0x00040] in <cf0a6fe010b14eed82a0909e12ee6695>:0 "