Error 3 The "LinkAssemblies" task failed unexpectedly. Xamarin.Android.XamarinAndroidException: error XA2006: Reference to metadata item 'System.Web.AspNetHostingPermissionLevel' (defined in 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a') from 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' could not be resolved. ---> Mono.Cecil.ResolutionException: Failed to resolve System.Web.AspNetHostingPermissionLevel at Mono.Cecil.Mixin.CheckedResolve(TypeReference self) at Mono.Cecil.SignatureReader.ReadCustomAttributeEnum(TypeReference enum_type) at Mono.Cecil.SignatureReader.ReadCustomAttributeElementValue(TypeReference type) at Mono.Cecil.SignatureReader.ReadCustomAttributeElement(TypeReference type) at Mono.Cecil.SignatureReader.ReadCustomAttributeFixedArgument(TypeReference type) at Mono.Cecil.SignatureReader.ReadCustomAttributeNamedArgument(Collection1& fields, Collection1& properties) at Mono.Cecil.SignatureReader.ReadCustomAttributeNamedArguments(UInt16 count, Collection1& fields, Collection1& properties) at Mono.Cecil.SignatureReader.ReadSecurityAttribute() at Mono.Cecil.MetadataReader.ReadSecurityDeclarationSignature(SecurityDeclaration declaration) at Mono.Cecil.SecurityDeclaration.m__1(SecurityDeclaration declaration, MetadataReader reader) at Mono.Cecil.ModuleDefinition.Read[TItem,TRet](TItem item, Func`3 read) at Mono.Cecil.SecurityDeclaration.Resolve() at Mono.Cecil.SecurityDeclaration.get_HasSecurityAttributes() at Mono.Linker.Steps.MarkStep.MarkSecurityDeclaration(SecurityDeclaration sd) at Mono.Linker.Steps.MarkStep.MarkSecurityDeclarations(ISecurityDeclarationProvider provider) at Mono.Linker.Steps.MarkStep.MarkType(TypeReference reference) at MonoDroid.Tuner.MonoDroidMarkStep.MarkType(TypeReference reference) at Mono.Linker.Steps.MarkStep.InitializeType(TypeDefinition type) at Mono.Linker.Steps.MarkStep.InitializeAssembly(AssemblyDefinition assembly) at Mono.Linker.Steps.MarkStep.Initialize() at Mono.Linker.Steps.MarkStep.Process(LinkContext context) at Mono.Linker.Pipeline.Process(LinkContext context) at MonoDroid.Tuner.Linker.Process(LinkerOptions options, LinkContext& context) at Xamarin.Android.Tasks.LinkAssemblies.Execute() --- End of inner exception stack trace --- at Xamarin.Android.Diagnostic.Error(Int32 code, Exception innerException, String message, Object[] args) at Xamarin.Android.Tasks.LinkAssemblies.Execute() at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute() at Microsoft.Build.BackEnd.TaskBuilder.d__20.MoveNext()