Xamarin.Forms - XamlCompilation MissingMethodException

Question

I want to improve performance of my Xamarin.Forms UWP application because it is extremely slow in Release mode (".NET native" checked). So I apply XAMLC at the assembly level in the PCL project:

[assembly: XamlCompilation (XamlCompilationOptions.Compile)]
namespace MyApp
{
}

but with this attribute I receive runtime error:

"Method not found: 'Void Xamarin.Forms.Xaml.Internals.SimpleValueTargetProvider..ctor(System.Object[])'."

According to this:

https://github.com/xamarin/Xamarin.Forms/blob/master/docs/Xamarin.Forms.Xaml/Xamarin.Forms.Xaml.Internals/SimpleValueTargetProvider.xml

the SimpleValueTargetProvider class has 2 versions:

• 1.5.0.0 - constructor with one parameter System.Object[]
• 2.0.0.0 - constructor with 2 parameters System.Object[] and System.Object

I use Xamarin.Forms 2.3.3.163-pre3 so I use the second version in my project (when I navigate to SimpleValueTargetProvider in Xamarin.Forms.Xaml.Internals I can see constructor with 2 parameters). My understanding is that apparently "something" is still calling SimpleValueTargetProvider 1.5.0.0, but I have no idea what it is.

I removed all of the third-party components but it did not help. I used fusion log to find out what is going on but this is all I get (to be honest I don't know if this is related to the issue I'm facing at all):

> *** Assembly Binder Log Entry  (10/26/2016 @ 9:09:42 PM) ***
> 
> The operation failed. Bind result: hr = 0x80070002. The system cannot
> find the file specified.
> 
> Assembly manager loaded from: 
> C:\Windows\Microsoft.NET\Framework\v4.0.30319\clr.dll Running under
> executable  C:\Program Files (x86)\Microsoft Visual
> Studio\VS15Preview\Common7\IDE\devenv.exe
> --- A detailed error log follows. 
> 
> === Pre-bind state information === LOG: DisplayName = XamlDesignerFaultInjection  (Partial) WRN: Partial binding information
> was supplied for an assembly: WRN: Assembly Name:
> XamlDesignerFaultInjection | Domain ID: 1 WRN: A partial bind occurs
> when only part of the assembly display name is provided. WRN: This
> might result in the binder loading an incorrect assembly. WRN: It is
> recommended to provide a fully specified textual identity for the
> assembly, WRN: that consists of the simple name, version, culture, and
> public key token. WRN: See whitepaper
> http://go.microsoft.com/fwlink/?LinkId=109270 for more information and
> common solutions to this issue. LOG: Appbase = file:///C:/Program
> Files (x86)/Microsoft Visual Studio/VS15Preview/Common7/IDE/ LOG:
> Initial PrivatePath = NULL LOG: Dynamic Base = NULL LOG: Cache Base =
> NULL LOG: AppName = devenv.exe Calling assembly : (Unknown).
> === LOG: This bind starts in default load context. LOG: Using application configuration file:
> C:\Users\blaze\AppData\Local\Microsoft\VisualStudio\15.0_2f751565\devenv.exe.config
> LOG: Using host configuration file:  LOG: Using machine configuration
> file from
> C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config.
> LOG: Policy not being applied to reference at this time (private,
> custom, partial, or location-based assembly bind). LOG: Attempting
> download of new URL file:///C:/Program Files (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/XamlDesignerFaultInjection.DLL. LOG:
> Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PublicAssemblies/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PublicAssemblies/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/Debugger/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/Debugger/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/DiagnosticsHub/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/DiagnosticsHub/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/x86/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/x86/XamlDesignerFaultInjection/XamlDesignerFaultInjection.DLL.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/XamlDesignerFaultInjection.EXE. LOG:
> Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PublicAssemblies/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PublicAssemblies/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Microsoft/TemplateProviders/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/Debugger/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/Debugger/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/DiagnosticsHub/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/CommonExtensions/Platform/DiagnosticsHub/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/x86/XamlDesignerFaultInjection.EXE.
> LOG: Attempting download of new URL file:///C:/Program Files
> (x86)/Microsoft Visual
> Studio/VS15Preview/Common7/IDE/PrivateAssemblies/DataCollectors/x86/XamlDesignerFaultInjection/XamlDesignerFaultInjection.EXE.
> LOG: All probing URLs attempted and failed.

Is this a bug in Xamarin.Forms or XamlCTask? Has anyone encountered this issue or knows how to fix it?

• Windows 10 64-bit
• Visual Studion 15 Preview 5
• Xamarin 4.2.1.14
• Xamarin.Forms 2.3.3.163-pre3

Thanks in advance

Answer 1

If your project depends on a 3rd party assembly that uses XamlC, and if that assembly has been build on XF<2.3.3, you still can get this issue.

A fix exists and will be released as part of the first service release for XF 2.3.3