FsXaml.Wpf.TypeProvider cannot be loaded

Question

I'm trying to use WPF with F#. I've created a project using the F# Empty Windows App template (in fact, I've created several using different settings). Then I added the FSharp.ViewModule and FsXaml.Wpf references. It works fine when the project only had MainWindow.xaml and MainWindow.xaml.fs. But as soon as I added another .xaml View file and a .fs ViewModel file, I get the following error on the "namespace ViewModels" declaration at the top of the .fs files:

The type provider '...\packages\FsXaml.Wpf.2.1.0\lib\net45\FsXaml.Wpf.TypeProvider.dll' reported an error: Assembly attribute 'TypeProviderAssemblyAttribute' refers to a designer assembly 'FsXaml.Wpf.TypeProvider' which cannot be loaded or doesn't exist. Could not load file or assembly 'file:///...\packages\FsXaml.Wpf.2.1.0\lib\net45\FsXaml.Wpf.TypeProvider.dll' or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)

There's a similar problem described in the post "FsXaml load error" (which I can't add comments to because I don't have enough reputation). But I've tried both the answers given there - changing the CPU and the F# runtime - and neither one works.

I'm using Visual Studio 2015 Community edition in a Windows 7 SP1 64-bit virtual machine. And I've tried using the following framework and DLL versions:

NET Framework 4.5 and 4.6
F# 3.0 and 4.0
FSharp.ViewModule 0.9.9 and 0.9.9.3
FsXaml.Wpf 2.0.0 and 2.1.0

EDIT 1: In reply to Reed's comment below, here are my two code files that are showing the errors. First, MainWindow.xaml.fs:

namespace ViewModels
open FSharp.ViewModule
open FsXaml

type MainView = XAML<"MainWindow.xaml", true>

type MainViewModel() as self = 
    inherit ViewModelBase()    

    let text = self.Factory.Backing (<@ self.Text @>, "")

    let newCommand = self.Factory.CommandSync (fun _ -> self.Text <- "File > Open")
    let openCommand = self.Factory.CommandSync(fun _ -> self.Text <- "File > Open")
    let closeCommand = self.Factory.CommandSync(fun _ -> self.Text <- "File > Close")
    let exitCommand = self.Factory.CommandSync(fun _ -> self.Text <- "File > Exit")

    member x.Text with get() = text.Value and set value = text.Value <- value

    member x.NewCommand = newCommand
    member x.OpenCommand = openCommand
    member x.CloseCommand = closeCommand
    member x.ExitCommand = exitCommand

And here's Dialog.fs:

namespace ViewModels
open FSharp.ViewModule

type DialogView = XAML<"Dialog.xaml", true>

type DialogVM() as self =
    inherit ViewModelBase()    

    let name = self.Factory.Backing (<@ self.Name @>, "")
    let address = self.Factory.Backing (<@ self.Address @>, "")

    member x.Name with get() = name.Value and set value = name.Value <- value
    member x.Address with get() = address.Value and set value = address.Value <- value

In both files I get red, squiggly lines under namespace ViewModels and under XAML. The project would build when it only had MainWindow.xaml.fs, but not since I added Dialog.fs

EDIT 2: Here's my .fsproj file

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">x86</Platform>
    <ProductVersion>8.0.30703</ProductVersion>
    <SchemaVersion>2.0</SchemaVersion>
    <ProjectGuid>b765eaca-f0ed-4898-bfea-fa19fca3788d</ProjectGuid>
    <OutputType>WinExe</OutputType>
    <RootNamespace>Test</RootNamespace>
    <AssemblyName>Test</AssemblyName>
    <targetframeworkversion>v4.5</targetframeworkversion>
    <TargetFSharpCoreVersion>4.3.0.0</TargetFSharpCoreVersion>
    <Name>Test</Name>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|x86' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <Tailcalls>false</Tailcalls>
    <OutputPath>bin\Debug\</OutputPath>
    <DefineConstants>DEBUG;TRACE</DefineConstants>
    <WarningLevel>3</WarningLevel>
    <PlatformTarget>x86</PlatformTarget>
    <DocumentationFile>bin\Debug\Test.XML</DocumentationFile>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|x86' ">
    <DebugType>pdbonly</DebugType>
    <Optimize>true</Optimize>
    <Tailcalls>true</Tailcalls>
    <OutputPath>bin\Release\</OutputPath>
    <DefineConstants>TRACE</DefineConstants>
    <WarningLevel>3</WarningLevel>
    <PlatformTarget>x86</PlatformTarget>
    <DocumentationFile>bin\Release\Test.XML</DocumentationFile>
  </PropertyGroup>
  <PropertyGroup>
    <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>
  </PropertyGroup>
  <Choose>
    <When Condition="'$(VisualStudioVersion)' == '11.0'">
      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets')">
        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\..\Microsoft SDKs\F#\3.0\Framework\v4.0\Microsoft.FSharp.Targets</FSharpTargetsPath>
      </PropertyGroup>
    </When>
    <Otherwise>
      <PropertyGroup Condition="Exists('$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets')">
        <FSharpTargetsPath>$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)\FSharp\Microsoft.FSharp.Targets</FSharpTargetsPath>
      </PropertyGroup>
    </Otherwise>
  </Choose>
  <Import Project="$(FSharpTargetsPath)" />
  <ItemGroup>
    <None Include="Dialog.xaml" />
    <Compile Include="Dialog.fs" />
    <Resource Include="MainWindow.xaml" />
    <Compile Include="MainWindow.xaml.fs" />
    <Resource Include="App.xaml" />
    <Compile Include="App.fs" />
    <Content Include="App.config" />
    <Content Include="packages.config" />
  </ItemGroup>
  <ItemGroup>
    <Reference Include="Accessibility" />
    <Reference Include="FSharp.ViewModule.Core.Wpf">
      <HintPath>..\..\packages\FSharp.ViewModule.Core.0.9.9.1\lib\net45\FSharp.ViewModule.Core.Wpf.dll</HintPath>
      <Private>True</Private>
    </Reference>
    <Reference Include="FsXaml.Wpf">
      <HintPath>..\..\packages\FsXaml.Wpf.0.9.9\lib\net45\FsXaml.Wpf.dll</HintPath>
      <Private>True</Private>
    </Reference>
    <Reference Include="FsXaml.Wpf.TypeProvider">
      <HintPath>..\..\packages\FsXaml.Wpf.0.9.9\lib\net45\FsXaml.Wpf.TypeProvider.dll</HintPath>
      <Private>True</Private>
    </Reference>
    <Reference Include="mscorlib" />
    <Reference Include="FSharp.Core, Version=$(TargetFSharpCoreVersion), Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
      <Private>True</Private>
    </Reference>
    <Reference Include="PresentationCore" />
    <Reference Include="PresentationFramework" />
    <Reference Include="PresentationUI" />
    <Reference Include="System" />
    <Reference Include="System.Core" />
    <Reference Include="System.Data" />
    <Reference Include="System.Drawing" />
    <Reference Include="System.Numerics" />
    <Reference Include="System.Windows.Interactivity">
      <HintPath>..\..\packages\Expression.Blend.Sdk.1.0.2\lib\net45\System.Windows.Interactivity.dll</HintPath>
      <Private>True</Private>
    </Reference>
    <Reference Include="System.Xaml" />
    <Reference Include="System.Xml" />
    <Reference Include="UIAutomationProvider" />
    <Reference Include="UIAutomationTypes" />
    <Reference Include="WindowsBase" />
  </ItemGroup>
</Project>

EDIT 3: App.fs is giving the error "The field, constructor, or member 'Root' is not defined.

module main
open System
open FsXaml

type App = XAML<"App.xaml">

[<STAThread>]
[<EntryPoint>]
let main argv =
    App().Root.Run()

And packages.config is giving the warning "The 'packages' element is not declared".

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Expression.Blend.Sdk" version="1.0.2" targetFramework="net45" />
  <package id="FSharp.ViewModule.Core" version="0.9.9.3" targetFramework="net45" />
  <package id="FsXaml.Wpf" version="2.1.0" targetFramework="net45" />
</packages>

Does \packages\FsXaml.Wpf.2.1.0\lib\net45\FsXaml.Wpf.TypeProvider.dll exist? Try some of the answers in this question http://stackoverflow.com/questions/21753979/visual-studio-could-not-load-file-or-assembly-operation-is-not-supported-erro — , Nov 28 '16 at 14:32
If that doesn't work - you might need to show code and the actual error/location/etc. — Reed Copsey, Nov 28 '16 at 21:52
@Will - yes the file does exist in the folder that it states. — DenisV, Nov 29 '16 at 03:55
@Foggy Finder - In my project tree from top to bottom I have Dialog.xaml (view), Dialog.fs (viewmodel), MainWindow.xaml, and MainWindow.xaml.fs — DenisV, Nov 29 '16 at 04:02
If it exists then you need to spin up fusion logger and see why the loader can't find it. — , Nov 29 '16 at 14:23
so, the problem is solved or not? Faster to write it in the chat [F# chat](http://chat.stackoverflow.com/rooms/51909/f) — FoggyFinder, Dec 01 '16 at 09:23

score 3 · Accepted Answer · answered Nov 30 '16 at 00:01

3

In the current version of FsXaml (2.1, and also 2.0), you no longer include the 2nd static parameter:

 type MainView = XAML<"MainWindow.xaml"> // Remove the 2nd arg here ...

Also, in Dialog.fs, you need to add open FsXaml:

namespace ViewModels
open FSharp.ViewModule
open FsXaml // This is probably causing the specific error you're seeing

type DialogView = XAML<"Dialog.xaml"> // Again, remove the true

I would recommend using F# 4 (3.1 or later is required), and the latest FsXaml and FSharp.ViewModule.

answered Nov 30 '16 at 00:01

Reed Copsey

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Thanks Reed, I'm almost there! But after making those changes and using the latest versions of FsXaml and FSharp.ViewModule, I'm still getting an error on 'Root' in App.fs that's stopping it from building, and a warning in packages.config - see EDIT 3 above. – DenisV Dec 01 '16 at 05:16
1

@DenisV remove .Root ... it's not needed now. the packages is a false warning. Close it in VS and it'll go away. – Reed Copsey Dec 01 '16 at 05:18

FsXaml.Wpf.TypeProvider cannot be loaded

1 Answers1