Link problem with SDK and User assemblies

I have a Xaml forms project which runs fin in debug or release mode with no link option set.

However if I link it with the SDK and User assemblies option then it crashes when I run it as shown below:
The missing method is only referred to from the XAML - is the linker not including it? Or how do I resolve the issue?

08-11 17:25:07.015 I/MonoDroid( 1594): UNHANDLED EXCEPTION: Xamarin.Forms.Xaml.XamlParseException: Position 200:14. No method OnresultButtonClicked found on type CelticTicPick.TicPickMainPage
08-11 17:25:07.015 I/MonoDroid( 1594): at Xamarin.Forms.Xaml.BaseValueNode.SetPropertyValue (System.Object xamlelement, XmlName propertyName, System.Object value, Xamarin.Forms.BindableObject rootElement) [0x00000] in :0
08-11 17:25:07.015 I/MonoDroid( 1594): 08-11 17:25:07.015 I/MonoDroid( 1594): at Xamarin.Forms.Xaml.ValueNode.ApplyTo (System.Object source, XmlName propertyName, Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:07.015 I/MonoDroid( 1594): at Xamarin.Forms.Xaml.INodeExtension.ApplyProperties (IElementNode node, System.Object source, Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:07.015 I/MonoDroid( 1594): at Xamarin.Forms.Xaml.ElementNode.ApplyProperties (System.Object source, Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:07.015 I/MonoDroid( 1594): at Xamarin.Forms.Xaml.ElementNode.<.ctor>b__0 () [0x00000] in :0
08-11 17:25:07.015 I/MonoDroid( 1594): at System.Lazy`1[System.Object].InitValue () [0x00000] in :0
Unhandled Exception:

Xamarin.Forms.Xaml.XamlParseException: Position 200:14. No method OnresultButtonClicked found on type CelticTicPick.TicPickMainPage

08-11 17:25:10.931 E/mono ( 1594):
08-11 17:25:10.931 E/mono ( 1594): Unhandled Exception:
08-11 17:25:10.931 E/mono ( 1594): Xamarin.Forms.Xaml.XamlParseException: Position 200:14. No method OnresultButtonClicked found on type CelticTicPick.TicPickMainPage
08-11 17:25:10.931 E/mono ( 1594): at Xamarin.Forms.Xaml.BaseValueNode.SetPropertyValue (System.Object xamlelement, XmlName propertyName, System.Object value, Xamarin.Forms.BindableObject rootElement) [0x00000] in :0
08-11 17:25:10.931 E/mono ( 1594): at Xamarin.Forms.Xaml.ValueNode.ApplyTo (System.Object source, XmlName propertyName, Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:10.931 E/mono ( 1594): at Xamarin.Forms.Xaml.INodeExtension.ApplyProperties (IElementNode node, System.Object source, Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:10.931 E/mono ( 1594): at Xamarin.Forms.Xaml.ElementNode.ApplyProperties (System.Object source, Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:10.931 E/mono ( 1594): at Xamarin.Forms.Xaml.ElementNode.Create (Boolean dontUseLazy) [0x00000] in :0
08-11 17:25:10.931 E/mono ( 1594): at Xamarin.Forms.Xaml.ElementNode.<.ctor>b__0 () [0x00000] in :0
08-11 17:25:10.931 E/mono ( 1594): at System.Lazy

1[System.Object].InitValue () [0x000
08-11 17:25:10.931 E/mono-rt ( 1594): [ERROR] FATAL UNHANDLED EXCEPTION: Xamarin.Forms.Xaml.XamlParseException: Position 200:14. No method OnresultButtonClicked found on type CelticTicPick.TicPickMainPage
08-11 17:25:10.931 E/mono-rt ( 1594):   at Xamarin.Forms.Xaml.BaseValueNode.SetPropertyValue (System.Object xamlelement, XmlName propertyName, System.Object value, Xamarin.Forms.BindableObject rootElement) [0x00000] in <filename unknown>:0 
08-11 17:25:10.931 E/mono-rt ( 1594):   at Xamarin.Forms.Xaml.ValueNode.ApplyTo (System.Object source, XmlName propertyName, Boolean dontUseLazy) [0x00000] in <filename unknown>:0 
08-11 17:25:10.931 E/mono-rt ( 1594):   at Xamarin.Forms.Xaml.INodeExtension.ApplyProperties (IElementNode node, System.Object source, Boolean dontUseLazy) [0x00000] in <filename unknown>:0 
08-11 17:25:10.931 E/mono-rt ( 1594):   at Xamarin.Forms.Xaml.ElementNode.ApplyProperties (System.Object source, Boolean dontUseLazy) [0x00000] in <filename unknown>:0 
08-11 17:25:10.931 E/mono-rt ( 1594):   at Xamarin.Forms.Xaml.ElementNode.Create (Boolean dontUseLazy) [0x00000] in <filename unknown>:0 
08-11 17:25:10.931 E/mono-rt ( 1594):   at Xamarin.Forms.Xaml.ElementNode.<.ctor>b__0 () [0x00000] in <filename unknown>:0 
08-11 17:25:10.931 E/mono-rt ( 1594):   at System.Lazy