Here is the error code.
Verbose: Loading Assets from Package [Xenko.xkpkg]
Error: Unexpected error while loading project [C:\Users\Ninekorn\Documents\Xenko Projects\VRSandbox\VRSandbox\VRSandbox.Game\VRSandbox.Game.csproj] or assembly reference []. Microsoft.Build.Exceptions.InvalidProjectFileException: The tools version “15.0” is unrecognized. Available tools versions are “2.0”, “3.5”, “4.0”. C:\Users\Ninekorn\Documents\Xenko Projects\VRSandbox\VRSandbox\VRSandbox.Game\VRSandbox.Game.csproj
at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args)
at Microsoft.Build.Evaluation.Project.Data.InitializeForEvaluation(IToolsetProvider toolsetProvider)
at Microsoft.Build.Evaluation.Evaluator4..ctor(IEvaluatorData4 data, ProjectRootElement projectRootElement, ProjectLoadSettings loadSettings, Int32 maxNodeCount, PropertyDictionary1 environmentProperties, ILoggingService loggingService, IItemFactory2 itemFactory, IToolsetProvider toolsetProvider, ProjectRootElementCache projectRootElementCache, BuildEventContext buildEventContext, ProjectInstance projectInstanceIfAnyForDebuggerOnly)
at Microsoft.Build.Evaluation.Project.Reevaluate(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings)
at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings)
at Microsoft.Build.Evaluation.Project.Initialize(IDictionary2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.Project..ctor(String projectFile, IDictionary2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectCollection projectCollection, ProjectLoadSettings loadSettings)
at Microsoft.Build.Evaluation.ProjectCollection.LoadProject(String fileName, IDictionary2 globalProperties, String toolsVersion) at SiliconStudio.Assets.VSProjectHelper.LoadProject(String fullProjectLocation, String configuration, String platform, Dictionary2 extraProperties) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\VSProjectHelper.cs:line 200
at SiliconStudio.Assets.VSProjectHelper.GetOrCompileProjectAssembly(String solutionFullPath, String fullProjectLocation, ILogger logger, String targets, Boolean autoCompileProject, Boolean forceNugetRestore, String configuration, String platform, Dictionary2 extraProperties, Boolean onlyErrors, BuildRequestDataFlags flags) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\VSProjectHelper.cs:line 76 at SiliconStudio.Assets.Package.LoadAssemblyReferencesForPackage(ILogger log, PackageLoadParameters loadParameters) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\Package.cs:line 1146 Error: Error while pre-loading package [SiliconStudio.Assets.Package]. Microsoft.Build.Exceptions.InvalidProjectFileException: The tools version "15.0" is unrecognized. Available tools versions are "2.0", "3.5", "4.0". C:\Users\Ninekorn\Documents\Xenko Projects\VRSandbox\VRSandbox\VRSandbox.Game\VRSandbox.Game.csproj at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args) at Microsoft.Build.Evaluation.Project.Data.InitializeForEvaluation(IToolsetProvider toolsetProvider) at Microsoft.Build.Evaluation.Evaluator4…ctor(IEvaluatorData4 data, ProjectRootElement projectRootElement, ProjectLoadSettings loadSettings, Int32 maxNodeCount, PropertyDictionary1 environmentProperties, ILoggingService loggingService, IItemFactory2 itemFactory, IToolsetProvider toolsetProvider, ProjectRootElementCache projectRootElementCache, BuildEventContext buildEventContext, ProjectInstance projectInstanceIfAnyForDebuggerOnly) at Microsoft.Build.Evaluation.Project.Reevaluate(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.Project.Initialize(IDictionary2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectLoadSettings loadSettings)
at Microsoft.Build.Evaluation.Project…ctor(String projectFile, IDictionary2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectCollection projectCollection, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.ProjectCollection.LoadProject(String fileName, IDictionary2 globalProperties, String toolsVersion)
at SiliconStudio.Assets.VSProjectHelper.LoadProject(String fullProjectLocation, String configuration, String platform, Dictionary2 extraProperties) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\VSProjectHelper.cs:line 200 at SiliconStudio.Assets.Package.FindAssetsInProject(String projectFullPath, String& nameSpace) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\Package.cs:line 1380 at SiliconStudio.Assets.Package.FindAssetsInProject(ICollection1 list, Package package) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\Package.cs:line 1407
at SiliconStudio.Assets.Package.ListAssetFiles(ILogger log, Package package, Boolean listAssetsInMsbuild, Nullable1 cancelToken) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\Package.cs:line 1374 at SiliconStudio.Assets.PackageSession.TryLoadAssets(PackageSession session, ILogger log, Package package, PackageLoadParameters loadParameters) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\PackageSession.cs:line 1019 Verbose: Compiling game assemblies... Error: Unexpected error while loading project [C:\Users\Ninekorn\Documents\Xenko Projects\VRSandbox\VRSandbox\VRSandbox.Game\VRSandbox.Game.csproj] or assembly reference []. Microsoft.Build.Exceptions.InvalidProjectFileException: The tools version "15.0" is unrecognized. Available tools versions are "2.0", "3.5", "4.0". C:\Users\Ninekorn\Documents\Xenko Projects\VRSandbox\VRSandbox\VRSandbox.Game\VRSandbox.Game.csproj at Microsoft.Build.Shared.ProjectErrorUtilities.ThrowInvalidProject(String errorSubCategoryResourceName, IElementLocation elementLocation, String resourceName, Object[] args) at Microsoft.Build.Evaluation.Project.Data.InitializeForEvaluation(IToolsetProvider toolsetProvider) at Microsoft.Build.Evaluation.Evaluator4…ctor(IEvaluatorData4 data, ProjectRootElement projectRootElement, ProjectLoadSettings loadSettings, Int32 maxNodeCount, PropertyDictionary1 environmentProperties, ILoggingService loggingService, IItemFactory2 itemFactory, IToolsetProvider toolsetProvider, ProjectRootElementCache projectRootElementCache, BuildEventContext buildEventContext, ProjectInstance projectInstanceIfAnyForDebuggerOnly) at Microsoft.Build.Evaluation.Project.Reevaluate(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.Project.ReevaluateIfNecessary(ILoggingService loggingServiceForEvaluation, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.Project.Initialize(IDictionary2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectLoadSettings loadSettings)
at Microsoft.Build.Evaluation.Project…ctor(String projectFile, IDictionary2 globalProperties, String toolsVersion, String subToolsetVersion, ProjectCollection projectCollection, ProjectLoadSettings loadSettings) at Microsoft.Build.Evaluation.ProjectCollection.LoadProject(String fileName, IDictionary2 globalProperties, String toolsVersion)
at SiliconStudio.Assets.VSProjectHelper.LoadProject(String fullProjectLocation, String configuration, String platform, Dictionary2 extraProperties) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\VSProjectHelper.cs:line 200 at SiliconStudio.Assets.VSProjectHelper.GetOrCompileProjectAssembly(String solutionFullPath, String fullProjectLocation, ILogger logger, String targets, Boolean autoCompileProject, Boolean forceNugetRestore, String configuration, String platform, Dictionary2 extraProperties, Boolean onlyErrors, BuildRequestDataFlags flags) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\VSProjectHelper.cs:line 76
at SiliconStudio.Assets.Package.LoadAssemblyReferencesForPackage(ILogger log, PackageLoadParameters loadParameters) in C:\TeamCity\work\80a49494ba341a6a\sources\assets\SiliconStudio.Assets\Package.cs:line 1146
Verbose: Game assemblies compiled…
Error: Could not find game settings asset at location [GameSettings]
Verbose: Restoring NuGet packages…
Is is unfortunately an issue in MSBuild (see https://github.com/Microsoft/msbuild/issues/2427 and https://github.com/Microsoft/msbuild/issues/2369). I noticed that this usually happens after either updating Visual Studio (especially 15.3) or installing another version side-by-side.
You can maybe find some help in this other thread: Unable to create new projects or load old projects notably the tool suggested by @Nejat to clean the installation
Reinstalling a fresh version of Visual Studio usually fixes it. Also note that for the moment we don’t support Visual Studio 15.3 (especially latest Xamarin) so I will advice against updating to the latest version.
Hi Kryptos,
Thank you for your answer.
How long until this is fixed? I use my PC for other projects as well (Xamarin) and don’t feel comfortable messing with the Visual Studio installation for sake of this defect.
I would assume that Xenko probably views this as a defect, right? Or is it something that you view as a MS defect and probably won’t be fixed?
If I install and use Visual Studio 2013, or earlier, instead – will that work in lieu of my VStudio2015 (which I don’t want to modify).
To give you a background on myself and my intentions with Xenko. We are porting a personal project of my son’s from XNA to Xenko. We purposefully left the graphics very crude, as we were intending to migrate this to Paradox eventually, and now Xenko.
My goal is for my son to learn C#/.NET programming while creating this game. He’s now 17. Currently, we’re just a 2-man team. Because Xenko is pure .NET, that makes it extremely attractive to us.
I can’t wait to get started, but currently this Visual Studio 2015 bug is standing in our way.
As further background on myself, I am Najak, the CTO/co-author/co-Founder of Visual3D.NET, the pure C# game engine which did NOT succeed (it was a house of cards, built too fast with too small budget with too many lesser experienced developers).
Here’s a link to a video for Visual3D.NET, that I created, and narrated. This engine is no longer available. Although we could do decent things with it, it has too many issues to be usable by others.
From what I understand this is how VS 2017 15.3 MSBuild API is going to work. They changed it in 15.3, they did not break it. Xenko needs to be updated to reflect this change. I hope if Xenko wants people to pay for it, they will have good support for this kind of thing.
I can still build my game using Visual Studio, but there are errors that don’t make sense in Xenko when I try to build.
Nope. It is definitely a regression on Microsoft side. See https://github.com/Microsoft/msbuild/issues/2369
That said I have a workaround for this issue that is going to be released soon.
Edit: Version 2.0.4.1 released with a fix that should prevent this issue.
I’m receiving this error of about 3-4 days ago on projects. A fresh install of Visual Studio fixes it but after a reboot or a day or so it seems this comes right back. Any help is appreciated. Is there a particular version of Visual Studio that works best? The daily setbacks are killing my timelines 
Visual Studio 2017 works great. That is what I use.