Visual studio Xamarin Visual Studio错误MSB4064和MSB4063

我在创建一个新的空白Xamarin项目后出现错误。一旦生成项目，我就会得到错误：

警告IDE0006加载项目时遇到错误。某些项目功能（如失败项目的完整解决方案分析和依赖于它的项目）已被禁用。Droid2 1激活

警告“Csc”任务不支持“ChecksumAlgorithm”参数。验证任务上是否存在该参数，以及该参数是否为可设置的公共实例属性。机器人2

警告“Csc”任务无法使用其输入参数初始化。机器人2

我尝试过多次卸载Xamarin并重新安装，但都没有成功

构建日志文件太大，无法完整添加，所以我只添加了最后一位。（30000字符限制）

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如果您运行的是Visual Studio 2015 Update 3，这里发布了一个解决方法-

在Update 3之后，我遇到了相同的问题，并且我的项目文件的顺序正确。一位同事帮我排除故障。结果是我安装了Roslyn Insiders扩展，并且它很高地提升了编译器。一旦我移除了那个分机，一切又恢复正常了

如果它发生在

Xamarin.Forms

NuGet程序包更新之后：

清理NuGet缓存（将清理当前目录及以下目录中的所有缓存NuGet）

封闭解决方案。退出VisualStudio以获得良好的度量并重新开始

---

我已经看过了。项目文件的顺序已经正确。我发现解决此问题的唯一方法是完全卸载Visual Studio 2015并重新安装。修复安装没有修复它。很高兴知道。我通过完全重新安装解决了这个问题。我不记得我是否安装了它，但我不会安装它们，直到它们成为发行版（如果有的话）。

    Target "_ExtractLibraryProjectImports" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Using "ReadLibraryProjectImportsCache" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
      Task "ReadLibraryProjectImportsCache"
        Task ReadLibraryProjectImportsCache
          CacheFile: obj\Debug\libraryprojectimports.cache
          Jars: 
          ResolvedAssetDirectories: 
          ResolvedResourceDirectories: 
          ResolvedEnvironmentFiles: 
          ResolvedResourceDirectoryStamps: 
      Done executing task "ReadLibraryProjectImportsCache".
    Done building target "_ExtractLibraryProjectImports" in project "Droid2.csproj".
    Target "_CrunchLibraryProjectImports" skipped, due to false condition; ( '$(AndroidExplicitCrunch)' == 'True' And '$(AndroidApplication)' != '' And $(AndroidApplication)) was evaluated as ( 'False' == 'True' And 'true' != '' And true).
    Target "_AddMultiDexDependencyJars" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Task "CreateItem" skipped, due to false condition; ('$(AndroidEnableMultiDex)' == 'True') was evaluated as ('False' == 'True').
    Done building target "_AddMultiDexDependencyJars" in project "Droid2.csproj".
    Target "_BuildLibraryImportsCache" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Skipping target "_BuildLibraryImportsCache" because all output files are up-to-date with respect to the input files.
      Input files: C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\Java.Interop.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v6.0\Mono.Android.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\mscorlib.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Core.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\Facades\System.Runtime.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Xml.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Xml.Linq.dll;D:\Play App\Droid2\Droid2\Droid2.csproj;obj\Debug\build.props
      Output files: obj\Debug\libraryimports.cache
    Done building target "_BuildLibraryImportsCache" in project "Droid2.csproj".
    Target "_GetLibraryImports" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Using "ReadImportedLibrariesCache" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
      Task "ReadImportedLibrariesCache"
        Task ReadImportedLibrariesCache
          CacheFile: obj\Debug\libraryimports.cache
          NativeLibraries: 
          Jars: 
          ManifestDocuments: 
      Done executing task "ReadImportedLibrariesCache".
      Task "CreateItem" skipped, due to false condition; ('@(ExtractedNativeLibraryImports)' != '') was evaluated as ('' != '').
    Done building target "_GetLibraryImports" in project "Droid2.csproj".
    Target "GetNativeProjectLibraries" skipped, due to false condition; ($(NativeAndroidInstalled)) was evaluated as (false).
    Target "_GetLibraryImports" skipped. Previously built successfully.
    Target "_CheckDuplicateJavaLibraries" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Using "CheckDuplicateJavaLibraries" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
      Task "CheckDuplicateJavaLibraries"
          JavaSourceFiles:
          JavaLibraries:
          LibraryProjectJars:
      Done executing task "CheckDuplicateJavaLibraries".
    Done building target "_CheckDuplicateJavaLibraries" in project "Droid2.csproj".
    Target "_ValidateResourceCache" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Using "ReadAdditionalResourcesFromAssemblyCache" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
      Task "ReadAdditionalResourcesFromAssemblyCache"
        Task ReadAdditionalResourcesFromAssemblyCache
          CacheFile: obj\Debug\resourcepaths.cache
          AdditionalAndroidResourcePaths: 
          AdditionalJavaLibraryReferences: 
          AdditionalNativeLibraryReferences: 
          IsValid: True
      Done executing task "ReadAdditionalResourcesFromAssemblyCache".
      Task "Delete" skipped, due to false condition; ( '$(_IsResourceCacheValid)' == 'False' ) was evaluated as ( 'True' == 'False' ).
    Done building target "_ValidateResourceCache" in project "Droid2.csproj".
    Target "_SetupDesignTimeBuildForIntellisense" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
    Done building target "_SetupDesignTimeBuildForIntellisense" in project "Droid2.csproj".
    Target "_BuildAdditionalResourcesCache" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Skipping target "_BuildAdditionalResourcesCache" because all output files are up-to-date with respect to the input files.
      Input files: C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\Java.Interop.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v6.0\Mono.Android.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\mscorlib.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Core.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\Facades\System.Runtime.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Xml.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Xml.Linq.dll
      Output files: obj\Debug\resourcepaths.cache
    Done building target "_BuildAdditionalResourcesCache" in project "Droid2.csproj".
    Target "_GetAdditionalResourcesFromAssemblies" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Task "ReadAdditionalResourcesFromAssemblyCache"
        Task ReadAdditionalResourcesFromAssemblyCache
          CacheFile: obj\Debug\resourcepaths.cache
          AdditionalAndroidResourcePaths: 
          AdditionalJavaLibraryReferences: 
          AdditionalNativeLibraryReferences: 
          IsValid: True
      Done executing task "ReadAdditionalResourcesFromAssemblyCache".
      Task "CreateItem" skipped, due to false condition; (Exists ('%(_AdditionalAndroidResourcePaths.Identity)\AndroidManifest.xml')) was evaluated as (Exists ('\AndroidManifest.xml')).
    Done building target "_GetAdditionalResourcesFromAssemblies" in project "Droid2.csproj".
    Target "_CalculateAdditionalResourceCacheDirectories" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Using "CalculateAdditionalResourceCacheDirectories" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
      Task "CalculateAdditionalResourceCacheDirectories"
        CalculateAdditionalResourceCacheDirectories Task
          AdditionalAndroidResourcePaths:
          CacheDirectory: obj\Debug\resourcecache
      Done executing task "CalculateAdditionalResourceCacheDirectories".
    Done building target "_CalculateAdditionalResourceCacheDirectories" in project "Droid2.csproj".
    Target "_GetAdditionalResourcesFromAssemblies" skipped. Previously built successfully.
    Target "_CreateAdditionalResourceCache" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Skipping target "_CreateAdditionalResourceCache" because it has no outputs.
      Though the target has declared its outputs, the output specification only references empty properties and/or empty item lists.
    Done building target "_CreateAdditionalResourceCache" in project "Droid2.csproj".
    Target "_ResolveMonoAndroidSdks" skipped. Previously built successfully.
    Target "_GenerateAndroidResourceDir" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Skipping target "_GenerateAndroidResourceDir" because all output files are up-to-date with respect to the input files.
      Input files: Resources\layout\Main.axml;Resources\values\Strings.xml;Resources\drawable\Icon.png;C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.CurrentVersion.targets;D:\Play App\Droid2\Droid2\Droid2.csproj;C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets;C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Xaml.targets;obj\Debug\build.props
      Output files: D:\Play App\Droid2\Droid2\obj\Debug\res\layout\main.xml;D:\Play App\Droid2\Droid2\obj\Debug\res\values\strings.xml;D:\Play App\Droid2\Droid2\obj\Debug\res\drawable\icon.png
    Done building target "_GenerateAndroidResourceDir" in project "Droid2.csproj".
    Target "_UpdateAndroidResgen" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Skipping target "_UpdateAndroidResgen" because all output files are up-to-date with respect to the input files.
      Input files: C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\Java.Interop.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v6.0\Mono.Android.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\mscorlib.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Core.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\Facades\System.Runtime.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Xml.dll;C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\MonoAndroid\v1.0\System.Xml.Linq.dll;D:\Play App\Droid2\Droid2\obj\Debug\res\layout\main.xml;D:\Play App\Droid2\Droid2\obj\Debug\res\values\strings.xml;D:\Play App\Droid2\Droid2\obj\Debug\res\drawable\icon.png;C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.CurrentVersion.targets;D:\Play App\Droid2\Droid2\Droid2.csproj;C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets;C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Xaml.targets
      Output files: obj\Debug\R.cs.flag
    Done building target "_UpdateAndroidResgen" in project "Droid2.csproj".
    Target "_AddLibraryProjectsEmbeddedResourceToProject" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
      Using "CreateManagedLibraryResourceArchive" task from assembly "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Build.Tasks.dll".
      Task "CreateManagedLibraryResourceArchive"
      Done executing task "CreateManagedLibraryResourceArchive".
      Task "CreateItem" skipped, due to false condition; (Exists ('$(IntermediateOutputPath)__AndroidLibraryProjects__.zip')) was evaluated as (Exists ('obj\Debug\__AndroidLibraryProjects__.zip')).
    Done building target "_AddLibraryProjectsEmbeddedResourceToProject" in project "Droid2.csproj".
    Target "_GenerateJavaDesignerForComponent" skipped, due to false condition; ('@(_AdditonalAndroidResourceCachePaths)' != '') was evaluated as ('' != '').
    Target "UpdateAndroidResources" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.Common.targets":
    Done building target "UpdateAndroidResources" in project "Droid2.csproj".
    Target "GetReferenceAssemblyPaths" skipped. Previously built successfully.
    Target "ImplicitlyExpandDesignTimeFacades" in file "C:\Program Files (x86)\MSBuild\Xamarin\Android\Xamarin.Android.PCLSupport.targets":
      Task "Message" skipped, due to false condition; ('%(ReferencePath.ResolvedFrom)' == 'ImplicitlyExpandDesignTimeFacades') was evaluated as ('{TargetFrameworkDirectory}' == 'ImplicitlyExpandDesignTimeFacades').
      Task "Message"
Done executing task "Message".
    Done building target "ImplicitlyExpandDesignTimeFacades" in project "Droid2.csproj".
    Target "ResolveReferences" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
    Done building target "ResolveReferences" in project "Droid2.csproj".
    Target "ResolveKeySource" skipped, due to false condition; ($(SignManifests) == 'true' or $(SignAssembly) == 'true') was evaluated as ( == 'true' or  == 'true').
    Target "ResolveComReferences" skipped, due to false condition; ('@(COMReference)'!='' or '@(COMFileReference)'!='') was evaluated as (''!='' or ''!='').
    Target "ResolveNativeReferences" skipped, due to false condition; ('@(NativeReference)'!='') was evaluated as (''!='').
    Target "_SetExternalWin32ManifestProperties" skipped, due to false condition; ('$(GenerateClickOnceManifests)'=='true' or '@(NativeReference)'!='' or '@(ResolvedIsolatedComModules)'!='') was evaluated as (''=='true' or ''!='' or ''!='').
    Target "_SetEmbeddedWin32ManifestProperties" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
      Using "GetFrameworkPath" task from assembly "Microsoft.Build.Tasks.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
      Task "GetFrameworkPath"
      Done executing task "GetFrameworkPath".
    Done building target "_SetEmbeddedWin32ManifestProperties" in project "Droid2.csproj".
    Target "SetWin32ManifestProperties" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
    Done building target "SetWin32ManifestProperties" in project "Droid2.csproj".
    Target "_GenerateCompileInputs" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
      Task "Warning" skipped, due to false condition; ('@(ManifestResourceWithNoCulture)'!='' and '%(ManifestResourceWithNoCulture.EmittedForCompatibilityOnly)'=='') was evaluated as (''!='' and ''=='').
      Task "Warning" skipped, due to false condition; ('@(ManifestNonResxWithNoCultureOnDisk)'!='' and '%(ManifestNonResxWithNoCultureOnDisk.EmittedForCompatibilityOnly)'=='') was evaluated as (''!='' and ''=='').
    Done building target "_GenerateCompileInputs" in project "Droid2.csproj".
    Target "PrepareForBuild" skipped. Previously built successfully.
    Target "GetReferenceAssemblyPaths" skipped. Previously built successfully.
    Target "_SetTargetFrameworkMonikerAttribute" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.CurrentVersion.targets":
    Done building target "_SetTargetFrameworkMonikerAttribute" in project "Droid2.csproj".
    Target "GenerateTargetFrameworkMonikerAttribute" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
      Skipping target "GenerateTargetFrameworkMonikerAttribute" because all output files are up-to-date with respect to the input files.
      Input files: C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.targets
      Output files: C:\Users\Ids\AppData\Local\Temp\MonoAndroid,Version=v6.0.AssemblyAttributes.cs
    Done building target "GenerateTargetFrameworkMonikerAttribute" in project "Droid2.csproj".
    Target "GenerateAdditionalSources" skipped, due to false condition; ('@(AssemblyAttributes)' != '' and '$(GenerateAdditionalSources)' == 'true') was evaluated as ('' != '' and '' == 'true').
    Target "BeforeCompile" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
    Done building target "BeforeCompile" in project "Droid2.csproj".
    Target "_TimeStampBeforeCompile" skipped, due to false condition; ('$(RunPostBuildEvent)'=='OnOutputUpdated' or ('$(RegisterForComInterop)'=='true' and '$(OutputType)'=='library')) was evaluated as (''=='OnOutputUpdated' or (''=='true' and 'Library'=='library')).
    Target "GenerateCompiledExpressionsTempFile" in file "C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Microsoft.WorkflowBuildExtensions.targets":
      Task "WriteLinesToFile" skipped, due to false condition; (!Exists('$(GenerateCompiledExpressionsTempFilePathForEditing)')) was evaluated as (!Exists('obj\Debug\\TemporaryGeneratedFile_E7A71F73-0F8D-4B9B-B56E-8E70B10BC5D3.cs')).
      Task "WriteLinesToFile" skipped, due to false condition; (!Exists('$(GenerateCompiledExpressionsTempFilePathForValidation)')) was evaluated as (!Exists('obj\Debug\\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs')).
      Task "WriteLinesToFile" skipped, due to false condition; (!Exists('$(GenerateCompiledExpressionsTempFilePathForTypeInfer)')) was evaluated as (!Exists('obj\Debug\\TemporaryGeneratedFile_5937a670-0e60-4077-877b-f7221da3dda1.cs')).
    Done building target "GenerateCompiledExpressionsTempFile" in project "Droid2.csproj".
    Target "DesignTimeXamlMarkupCompilation" in file "C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Microsoft.Xaml.targets":
      Task "MakeDir" skipped, due to false condition; ('@(XamlAppDef)' != '') was evaluated as ('' != '').
      Task "CallTarget" skipped, due to false condition; ('$(BuildingProject)' != 'true' and '@(XamlAppDef)' != '') was evaluated as ('false' != 'true' and '' != '').
    Done building target "DesignTimeXamlMarkupCompilation" in project "Droid2.csproj".
    Target "CleanInProcessXamlGeneratedFiles" skipped, due to false condition; ('@(XamlAppDef)' != '') was evaluated as ('' != '').
    Target "_ComputeNonExistentFileProperty" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.Common.CurrentVersion.targets":
    Done building target "_ComputeNonExistentFileProperty" in project "Droid2.csproj".
    Target "ResolveCodeAnalysisRuleSet" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.CurrentVersion.targets":
      Using "ResolveCodeAnalysisRuleSet" task from assembly "Microsoft.Build.Tasks.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
      Task "ResolveCodeAnalysisRuleSet"
      Done executing task "ResolveCodeAnalysisRuleSet".
    Done building target "ResolveCodeAnalysisRuleSet" in project "Droid2.csproj".
    Target "PreXsdCodeGen" in file "C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Microsoft.ServiceModel.targets":
      Using "CallTarget" task from assembly "Microsoft.Build.Tasks.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
      Task "CallTarget"
        Target "CleanXsdCodeGen" in file "C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Microsoft.ServiceModel.targets":
          Using "Delete" task from assembly "Microsoft.Build.Tasks.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".
          Task "Delete"
          Done executing task "Delete".
        Done building target "CleanXsdCodeGen" in project "Droid2.csproj".
      Done executing task "CallTarget".
    Done building target "PreXsdCodeGen" in project "Droid2.csproj".
    Target "XsdCodeGen" skipped, due to false condition; ( '$(XsdCodeGenPreCondition)' == 'True' ) was evaluated as ( 'False' == 'True' ).
    Target "CoreCompile" in file "C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.Core.targets":
      Building target "CoreCompile" completely.
      Output file "obj\Debug\Droid2.dll" does not exist.
      Using "Csc" task from assembly "C:\Users\Ids\AppData\Local\Microsoft\VisualStudio\14.0\Extensions\enunflvr.wib\Microsoft.Build.Tasks.CodeAnalysis.dll".
      Task "Csc"
        C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.Core.targets(76,11): error MSB4064: The "ChecksumAlgorithm" parameter is not supported by the "Csc" task. Verify the parameter exists on the task, and it is a settable public instance property.
        C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.Core.targets(67,5): error MSB4063: The "Csc" task could not be initialized with its input parameters. 
      Done executing task "Csc" -- FAILED.
    Done building target "CoreCompile" in project "Droid2.csproj" -- FAILED.
    
    Done building project "Droid2.csproj" -- FAILED.
    
    Project Performance Summary:
          125 ms  D:\Play App\Droid2\Droid2\Droid2.csproj    1 calls
    
    Target Performance Summary:
            0 ms  _AddMultiDexDependencyJars                 1 calls
            0 ms  ResolveSDKReferences                       1 calls
            0 ms  _SetupDesignTimeBuildForIntellisense       1 calls
            0 ms  GetInstalledSDKLocations                   1 calls
            0 ms  GetReferenceAssemblyPaths                  1 calls
            0 ms  _ValidateAndroidPackageProperties          1 calls
            0 ms  _CheckForInvalidConfigurationAndPlatform   1 calls
            0 ms  ResolveReferences                          1 calls
            0 ms  AssignProjectConfiguration                 1 calls
            0 ms  _GenerateCompileInputs                     1 calls
            0 ms  _BuildAdditionalResourcesCache             1 calls
            0 ms  _ResolveLibraryProjectImports              1 calls
            0 ms  _BuildSdkCache                             1 calls
            0 ms  GenerateTargetFrameworkMonikerAttribute    1 calls
            0 ms  ResolveProjectReferences                   1 calls
            0 ms  GetFrameworkPaths                          1 calls
            0 ms  _CalculateAdditionalResourceCacheDirectories   1 calls
            0 ms  AfterResolveReferences                     1 calls
            0 ms  _SetEmbeddedWin32ManifestProperties        1 calls
            0 ms  _CheckDuplicateJavaLibraries               1 calls
            0 ms  _GetLibraryImports                         1 calls
            0 ms  _GenerateAndroidAssetsDir                  1 calls
            0 ms  _ResolveMonoAndroidFramework               1 calls
            0 ms  _SeparateAppExtensionReferences            1 calls
            0 ms  _SplitProjectReferencesByFileExistence     1 calls
            0 ms  _BuildLibraryImportsCache                  1 calls
            0 ms  _ComputeNonExistentFileProperty            1 calls
            0 ms  _GenerateAndroidResourceDir                1 calls
            0 ms  SetWin32ManifestProperties                 1 calls
            0 ms  BeforeResolveReferences                    1 calls
            0 ms  _GetReferenceAssemblyPaths                 1 calls
            0 ms  CleanXsdCodeGen                            1 calls
            0 ms  _UpdateAndroidResgen                       1 calls
            0 ms  ModifyUnitTestPlatformVersion              1 calls
            0 ms  _ComputeAndroidResourcePaths               1 calls
            0 ms  _SetTargetFrameworkMonikerAttribute        1 calls
            0 ms  _AddLibraryProjectsEmbeddedResourceToProject   1 calls
            0 ms  UpdateAndroidResources                     1 calls
            0 ms  ExpandSDKReferences                        1 calls
            0 ms  BeforeCompile                              1 calls
            0 ms  PrepareForBuild                            1 calls
            0 ms  PreXsdCodeGen                              1 calls
            0 ms  _ExtractLibraryProjectImports              1 calls
            0 ms  ResolveCodeAnalysisRuleSet                 1 calls
            0 ms  _ComputeAndroidAssetsPaths                 1 calls
            0 ms  DesignTimeXamlMarkupCompilation            1 calls
            0 ms  _CheckForDeletedResourceFile               1 calls
            0 ms  _CreateAdditionalResourceCache             1 calls
            0 ms  _GetAdditionalResourcesFromAssemblies      1 calls
            0 ms  GenerateCompiledExpressionsTempFile        1 calls
            0 ms  UpdateAndroidAssets                        1 calls
           16 ms  _ResolveMonoAndroidSdks                    1 calls
           16 ms  ImplicitlyExpandDesignTimeFacades          1 calls
           16 ms  _ValidateResourceCache                     1 calls
           16 ms  CoreCompile                                1 calls
           31 ms  _SetLatestTargetFrameworkVersion           1 calls
           31 ms  ResolveAssemblyReferences                  1 calls
    
    Task Performance Summary:
            0 ms  CreateItem                                 1 calls
            0 ms  CallTarget                                 1 calls
            0 ms  FindAppConfigFile                          1 calls
            0 ms  GetAndroidPackageName                      1 calls
            0 ms  CreateProperty                            39 calls
            0 ms  ReadImportedLibrariesCache                 1 calls
            0 ms  Csc                                        1 calls
            0 ms  CreateManagedLibraryResourceArchive        1 calls
            0 ms  CheckDuplicateJavaLibraries                1 calls
            0 ms  ResolveCodeAnalysisRuleSet                 1 calls
            0 ms  GetReferenceAssemblyPaths                  2 calls
            0 ms  GetAppSettingsDirectory                    1 calls
            0 ms  Message                                   13 calls
            0 ms  Delete                                     1 calls
            0 ms  MakeDir                                    2 calls
            0 ms  ReadLibraryProjectImportsCache             1 calls
            0 ms  GetFrameworkPath                           1 calls
            0 ms  ReadResolvedSdksCache                      1 calls
            0 ms  AndroidComputeResPaths                     2 calls
            0 ms  GetJavaPlatformJar                         1 calls
            0 ms  CalculateAdditionalResourceCacheDirectories   1 calls
            0 ms  AssignProjectConfiguration                 1 calls
           16 ms  GetAndroidDefineConstants                  1 calls
           16 ms  ReadAdditionalResourcesFromAssemblyCache   2 calls
           31 ms  ResolveAssemblyReference                   1 calls
    
    Build FAILED.
    
    C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.Core.targets(76,11): error MSB4064: The "ChecksumAlgorithm" parameter is not supported by the "Csc" task. Verify the parameter exists on the task, and it is a settable public instance property.
    C:\Program Files (x86)\MSBuild\14.0\bin\Microsoft.CSharp.Core.targets(67,5): error MSB4063: The "Csc" task could not be initialized with its input parameters. 
        0 Warning(s)
        2 Error(s)
    
    Time Elapsed 00:00:00.14

rm -rf `find . -name "packages"` # exhaustive and efficient
nuget locals all -clear          # also clear cache