The "XamlCTask" task failed unexpectedly on visual studio for xamarin

Question

When I am trying to run application on Xamarin on visual studio, I am getting error as mentioned below and not able to run the application on device or emulator:

The "XamlCTask" task failed unexpectedly.
Microsoft.Cci.Pdb.PdbDebugException: Unknown custom metadata item kind: 6
   at Microsoft.Cci.Pdb.PdbFunction.ReadCustomMetadata(BitAccess bits)
   at Microsoft.Cci.Pdb.PdbFunction..ctor(ManProcSym proc, BitAccess bits)
   at Microsoft.Cci.Pdb.PdbFunction.LoadManagedFunctions(BitAccess bits, UInt32 limit, Boolean readStrings)
   at Microsoft.Cci.Pdb.PdbFile.LoadFuncsFromDbiModule(BitAccess bits, DbiModuleInfo info, IntHashTable names, ArrayList funcList, Boolean readStrings, MsfDirectory dir, Dictionary`2 nameIndex, PdbReader reader)
   at Microsoft.Cci.Pdb.PdbFile.LoadFunctions(Stream read, Dictionary`2& tokenToSourceMapping, String& sourceServerData)
   at Mono.Cecil.Pdb.PdbReader.PopulateFunctions()
   at Mono.Cecil.Pdb.PdbReader.ProcessDebugHeader(ImageDebugDirectory directory, Byte[] header)
   at Mono.Cecil.ModuleDefinition.ProcessDebugHeader()
   at Mono.Cecil.ModuleDefinition.ReadSymbols(ISymbolReader reader)
   at Mono.Cecil.ModuleReader.ReadSymbols(ModuleDefinition module, ReaderParameters parameters)
   at Mono.Cecil.ModuleReader.CreateModuleFrom(Image image, ReaderParameters parameters)
   at Mono.Cecil.ModuleDefinition.ReadModule(Stream stream, ReaderParameters parameters)
   at Mono.Cecil.ModuleDefinition.ReadModule(String fileName, ReaderParameters parameters)
   at Xamarin.Forms.Build.Tasks.XamlCTask.Compile()
   at Xamarin.Forms.Build.Tasks.XamlCTask.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__1.MoveNext()  MyFirstProject      

Before adding this "Xamarin.Forms.Maps" NuGet package, my application working but as I have added this suddenly application stops running and getting error.

Anybody could help me what causes this type of issue?

Answer 1

This issue arise, if your Xamarin.Form version is not compatible/matching with your NuGet package which you have installed.

So, I have just updated Xamarin.Forms for both xx.Droid and PCL and make the match the dependencies with NuGet package.

Now it is working fine. Hope so this will work for you.

Answer 2

Delete your old package /[your project root]/packages/Xamarin.Forms.[old version number].

Answer 3

This kind of issue may also come if by mistake you have any syntactical error like in my case: two text cells were present in the ListView -

<ListView x:Name="ProductsView">
    <ListView.ItemTemplate>
        <DataTemplate>
            <TextCell Text="{Binding ProductId}" />
            <TextCell Text="{Binding ProductDescription}" />
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

I went through other posts for this issue and found the same issue occurred due to the presence of syntactical errors, which VS doesn't report directly. So look for this, otherwise, reinstall the compatible version of xamarin.forms -> clean solutions -> rebuild by reopening VS.

Answer 4

I removed all Xamarin references from ALL projects, removed ALL Xamaring packages. Deleted all mention of Xamarin in PROJ files and readded all nuget packages for Xamarin. (lost days on this) :)