Adding WASM to existing Xamarin.Forms project throws multiple errors in different scenarios.

[albertoha94]

Current behavior

I recenlty tried Uno and decided to add it to an existing project I have using the information from Uno Platform for Xamarin.Forms Developers, at first I was getting issues regarding the version of the app but thankfully that was solved with the information provided with this Other issue.
Once I did this I was able to get the project running but it got stuck in the SplashScreen with the following errors:

fail: Windows.UI.Xaml.Controls.GroupStyleSelector[0]
dotnet.js:1       The member GroupStyleSelector.GroupStyleSelector() is not implemented in Uno.
dotnet.js:1 fail: Windows.UI.Xaml.Controls.CommandBarFlyout[0]
dotnet.js:1       The member CommandBarFlyout.CommandBarFlyout() is not implemented in Uno.
dotnet.js:1 fail: Windows.UI.Xaml.Controls.TextCommandBarFlyout[0]
dotnet.js:1       The member TextCommandBarFlyout.TextCommandBarFlyout() is not implemented in Uno.
dotnet.js:1 The Bindable attribute is missing and the type [XamarinForms.BlogBuilder.UWP.MainPage] is not known by the MetadataProvider. Reflection was used instead of the binding engine and generated static metadata. Add the Bindable attribute to prevent this message and performance issues.
dotnet.js:1 fail: Windows.UI.Core.CoreDispatcher[0]
dotnet.js:1       Dispatcher unhandled exception
dotnet.js:1 System.Exception: Failed to load Page XamarinForms.BlogBuilder.UWP.MainPage
dotnet.js:1   at XamarinForms.BlogBuilder.UWP.App.OnNavigationFailed (System.Object sender, Windows.UI.Xaml.Navigation.NavigationFailedEventArgs e) [0x00001] in D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.UWP\App.xaml.cs:86 
dotnet.js:1   at Windows.UI.Xaml.Controls.Frame.InnerNavigate (Windows.UI.Xaml.Navigation.PageStackEntry entry, Windows.UI.Xaml.Navigation.NavigationMode mode) <0x3d52368 + 0x0040c> in <filename unknown>:0 
dotnet.js:1   at Windows.UI.Xaml.Controls.Frame.Navigate (System.Type sourcePageType, System.Object parameter, Windows.UI.Xaml.Media.Animation.NavigationTransitionInfo infoOverride) <0x3d4c3b8 + 0x00022> in <filename unknown>:0 
dotnet.js:1   at Windows.UI.Xaml.Controls.Frame.Navigate (System.Type sourcePageType, System.Object parameter) <0x3d4c180 + 0x0000c> in <filename unknown>:0 
dotnet.js:1   at XamarinForms.BlogBuilder.UWP.App.OnLaunched (Windows.ApplicationModel.Activation.LaunchActivatedEventArgs e) [0x00089] in D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.UWP\App.xaml.cs:72 
dotnet.js:1   at Windows.UI.Xaml.Application.Initialize () <0x385a738 + 0x000dc> in <filename unknown>:0 
dotnet.js:1   at Windows.UI.Core.CoreDispatcher.DispatchItems () [0x0010e] in C:\a\1\s\src\Uno.UWP\UI\Core\CoreDispatcher.cs:310 
dotnet.js:1 L: GC_MINOR: (Nursery full) time 6.50ms, stw 6.50ms promoted 1249K major size: 3520K in use: 2857K los size: 1024K in use: 187K

I then checked if Uno was correctly installed by creating a new project and running Rpn Calculator, both ran successfully.
When checking Rpn Calculator, I saw a Shared Project and tried adding it in the same way in my project but that just gave me a different error:

Severity	Code	Description	Project	File	Line	Suppression State
Error	CS8646	'MainPage.IMainPage_Bindings.Initialize()' is explicitly implemented more than once.	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS8646	'MainPage.IMainPage_Bindings.StopTracking()' is explicitly implemented more than once.	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS8646	'MainPage.IMainPage_Bindings.Update()' is explicitly implemented more than once.	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS8646	'MainPage.IMainPage_Bindings.UpdateResources()' is explicitly implemented more than once.	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS0535	'MainPage.MainPage_Bindings' does not implement interface member 'MainPage.IMainPage_Bindings.Initialize()'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS0535	'MainPage.MainPage_Bindings' does not implement interface member 'MainPage.IMainPage_Bindings.StopTracking()'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS0535	'MainPage.MainPage_Bindings' does not implement interface member 'MainPage.IMainPage_Bindings.Update()'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS0535	'MainPage.MainPage_Bindings' does not implement interface member 'MainPage.IMainPage_Bindings.UpdateResources()'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_d09f3a5f3769f49d3a9ff57413f40153.g.cs	110	Active
Error	CS0756	A partial method may not have multiple defining declarations	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	86	Active
Error	CS0579	Duplicate 'global::System.Diagnostics.DebuggerNonUserCodeAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	109	Active
Error	CS0579	Duplicate 'System.Reflection.AssemblyCompanyAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\XamarinForms.BlogBuilder.Wasm.AssemblyInfo.cs	14	Active
Error	CS0579	Duplicate 'System.Reflection.AssemblyConfigurationAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\XamarinForms.BlogBuilder.Wasm.AssemblyInfo.cs	15	Active
Error	CS0579	Duplicate 'System.Reflection.AssemblyFileVersionAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\XamarinForms.BlogBuilder.Wasm.AssemblyInfo.cs	16	Active
Error	CS0579	Duplicate 'System.Reflection.AssemblyProductAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\XamarinForms.BlogBuilder.Wasm.AssemblyInfo.cs	18	Active
Error	CS0579	Duplicate 'System.Reflection.AssemblyTitleAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\XamarinForms.BlogBuilder.Wasm.AssemblyInfo.cs	19	Active
Error	CS0579	Duplicate 'System.Reflection.AssemblyVersionAttribute' attribute	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\XamarinForms.BlogBuilder.Wasm.AssemblyInfo.cs	20	Active
Error	CS0102	The type 'MainPage' already contains a definition for 'Bindings'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	107	Active
Error	CS0102	The type 'MainPage' already contains a definition for 'IMainPage_Bindings'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	99	Active
Error	CS0102	The type 'MainPage' already contains a definition for 'MainPage_Bindings'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	110	Active
Error	CS0102	The type 'MainPage' already contains a definition for '_component_0'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	88	Active
Error	CS0102	The type 'MainPage' already contains a definition for '_component_0_Holder'	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	87	Active
Error	CS0111	Type 'App' already defines a member called 'InitializeComponent' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\App_65db6ac9f205d8a4926dfe88db76652a.g.cs	49	Active
Error	CS0111	Type 'MainPage' already defines a member called 'InitializeComponent' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	49	Active
Error	CS0111	Type 'MainPage' already defines a member called 'OnInitializeCompleted' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	86	Active
Error	CS0111	Type 'MainPage.IMainPage_Bindings' already defines a member called 'Initialize' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	101	Active
Error	CS0111	Type 'MainPage.IMainPage_Bindings' already defines a member called 'StopTracking' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	104	Active
Error	CS0111	Type 'MainPage.IMainPage_Bindings' already defines a member called 'Update' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	102	Active
Error	CS0111	Type 'MainPage.IMainPage_Bindings' already defines a member called 'UpdateResources' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	103	Active
Error	CS0111	Type 'MainPage.MainPage_Bindings' already defines a member called '.ctor' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	118	Active
Error	CS0111	Type 'MainPage.MainPage_Bindings' already defines a member called 'XamarinForms.BlogBuilder.UWP.MainPage.IMainPage_Bindings.Initialize' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	122	Active
Error	CS0111	Type 'MainPage.MainPage_Bindings' already defines a member called 'XamarinForms.BlogBuilder.UWP.MainPage.IMainPage_Bindings.StopTracking' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	134	Active
Error	CS0111	Type 'MainPage.MainPage_Bindings' already defines a member called 'XamarinForms.BlogBuilder.UWP.MainPage.IMainPage_Bindings.Update' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	125	Active
Error	CS0111	Type 'MainPage.MainPage_Bindings' already defines a member called 'XamarinForms.BlogBuilder.UWP.MainPage.IMainPage_Bindings.UpdateResources' with the same parameter types	XamarinForms.BlogBuilder.Wasm	D:\Albertoha94\Documents\Visual Studio 2019\XamarinForms.BlogBuilder\XamarinForms.BlogBuilder.Wasm\obj\Debug\netstandard2.0\g\XamlCodeGenerator\MainPage_adcc0741659c2525a5de934144ea991e.g.cs	129	Active

Its worth noting that the second error only shows up if there's a reference to the Shared Project in the WASM project.
If there is no reference then I just get the first one but I'm uncertain which path to go.
In my project I was already using Dependency Injection, MVVM and Xamarin.Forms Shell so I don't know if something is related to this as well.

I will post 2 versions of the same project, One having the reference inside WASM and the second one not.
This to make sure which one is the right path to take and how to fix it.
Projects.zip

Expected behavior

The app should run with the given documentation.

How to reproduce it (as minimally and precisely as possible)

No response

Workaround

No workaround found so far.

Works on UWP/WinUI

Yes

Environment

No response

NuGet package version(s)

On Forms:
-NETStandard.Library 2.0.3
-SQLiteNetExtensions.Async 2.1.0
-sqlite-net-pcl 1.7.335
-TinyMvvm.Autofac 2.4.14
-TinyMvvm.Forms 2.4.14
-Xamarin.Essentials 1.6.1
-Xamarin.Forms 5.0.0.1931

On UWP:
-Microsoft.NETCore.UniversalWindowsPlatform 6.2.10
-Xamarin.Essentials 1.6.1
-Xamarin.Forms 5.0.0.1931

On WASM:
-Microsoft.Extensions.Logging.Console 1.1.1
-Microsoft.Extensions.Logging.Filter 1.1.1
-NETStandard.Library 2.0.3
-Uno.UI.WebAssembly 3.9.7
-Uno.Wasm.Bootstrap 1.3.0
-Uno.Wasm.Bootstrap.DevServer 1.3.0
-Uno.Xamarin.Forms.Platform 5.0.0-uno.1799

Affected platforms

WebAssembly

IDE

Visual Studio 2019

IDE version

16.7.5

Relevant plugins

Anything else we need to know?

No response

[jeromelaban]

Thanks for the report! For your first stack trace, it seems that there's an exception happening when the page is created. You may need to display the exception raised in the NavigationFailed event handler.

For the other log, it would seem that you included the shared project twice somehow.

[jeromelaban]

You can generally debug this using binlogs: https://platform.uno/docs/articles/uno-builds-troubleshooting.html#generating-msbuild-binary-log-files. Look out for double inclusions.

[albertoha94]

Good news,
After checking the project with the bin log.
I was able to remove and add the following items in WASM Csproj:

Removed:

<ItemGroup>
    <Compile Include="../XamarinForms.BlogBuilder.UWP/*.xaml.cs">
      <DependentUpon>%(FileName)</DependentUpon>
    </Compile>
    <Page Include="../XamarinForms.BlogBuilder.UWP/*.xaml" />
    <UpToDateCheckInput Include="../XamarinForms.BlogBuilder.UWP/*.xaml" />
</ItemGroup>

Added:

 <WasmHead>true</WasmHead>
 <GenerateAssemblyInfo>false</GenerateAssemblyInfo>

This made the app run again with the shared project but I still get the initial error happening OnNavigationFailed:
I added some logs to see if I could figure it out but no luck so far:
Here is the log with more details:

OnNavigationFailed log Start ---
dotnet.js:1 e.ToString:Windows.UI.Xaml.Navigation.NavigationFailedEventArgs
dotnet.js:1 e.Exception.Message:Exception has been thrown by the target of an invocation.
dotnet.js:1 e.Exception.Source:mscorlib
dotnet.js:1 e.Exception.StackTrace:  at System.Reflection.RuntimeConstructorInfo.InternalInvoke (System.Object obj, System.Object[] parameters, System.Boolean wrapExceptions) [0x00018] in /__w/1/s/mono/mcs/class/corlib/System.Reflection/RuntimeMethodInfo.cs:944 
dotnet.js:1   at System.RuntimeType.CreateInstanceMono (System.Boolean nonPublic, System.Boolean wrapExceptions) [0x00095] in /__w/1/s/mono/mcs/class/corlib/ReferenceSources/RuntimeType.cs:185 
dotnet.js:1   at System.RuntimeType.CreateInstanceSlow (System.Boolean publicOnly, System.Boolean wrapExceptions, System.Boolean skipCheckThis, System.Boolean fillCache) [0x00009] in /__w/1/s/mono/mcs/class/corlib/ReferenceSources/RuntimeType.cs:155 
dotnet.js:1   at System.RuntimeType.CreateInstanceDefaultCtor (System.Boolean publicOnly, System.Boolean skipCheckThis, System.Boolean fillCache, System.Boolean wrapExceptions, System.Threading.StackCrawlMark& stackMark) [0x00027] in /__w/1/s/mono/mcs/class/referencesource/mscorlib/system/rttype.cs:5767 
dotnet.js:1   at System.Activator.CreateInstance (System.Type type, System.Boolean nonPublic, System.Boolean wrapExceptions) [0x00039] in /__w/1/s/mono/mcs/class/referencesource/mscorlib/system/activator.cs:206 
dotnet.js:1   at System.Activator.CreateInstance (System.Type type, System.Boolean nonPublic) [0x00000] in /__w/1/s/mono/mcs/class/referencesource/mscorlib/system/activator.cs:190 
dotnet.js:1   at System.Activator.CreateInstance (System.Type type) [0x00000] in /__w/1/s/mono/mcs/class/referencesource/mscorlib/system/activator.cs:134 
dotnet.js:1   at Windows.UI.Xaml.Controls.Frame.CreatePageInstance (System.Type sourcePageType) <0x3d3bf90 + 0x00056> in <filename unknown>:0 
dotnet.js:1   at Windows.UI.Xaml.PagePool.DequeuePage (System.Type pageType) <0x3d3be30 + 0x00012> in <filename unknown>:0 
dotnet.js:1   at Windows.UI.Xaml.Controls.Frame.CreatePageInstanceCached (System.Type sourcePageType) <0x3d3bb28 + 0x0000e> in <filename unknown>:0 
dotnet.js:1   at Windows.UI.Xaml.Controls.Frame.InnerNavigate (Windows.UI.Xaml.Navigation.PageStackEntry entry, Windows.UI.Xaml.Navigation.NavigationMode mode) <0x3d3e7a8 + 0x00168> in <filename unknown>:0 
dotnet.js:1 e.Exception.HelpLink:
dotnet.js:1 e.Exception.TargetSite:System.Object InternalInvoke(System.Object, System.Object[], Boolean)
dotnet.js:1 e.Exception.Data:System.Collections.ListDictionaryInternal
dotnet.js:1 OnNavigationFailed log End ---

[albertoha94]

I am using MVVM, Dependency Injection and Shell, I am uncertain if something of that is breaking the app so I will post the most recent project with only the OnNavigationFailed issue.
XamarinForms.BlogBuilder.zip

[jeromelaban]

It look like the logging you added is not enough, where the created page is throwing another exception. You may need to dig into this exception first.

[albertoha94]

So I tried to set the MainPage an empty page and it worked.
It seems its related to the Autofac Dependency Injection or Xamarin Forms Shell, will have to take a look.
For simplicity I might change to ReactiveUI.Uno so that it works best, does Xamarin Forms Shell works on WASM?