Unable to find a usable version of MSBuild on this machine

I've installed the latest release of NCrunch for Visual Studio 2013, and cannot run any unit tests due to NCrunch failing to find MSBuild.

This is the call stack for the exception shown:

System.Exception: Unable to find a usable version of MSBuild on this machine.
at nCrunch.Core.BuildManagement.MSBuildEngineRegistry.GetBuildableProjectForVisualStudioVersion(VisualStudioVersion vsVersion)
at nCrunch.Core.BuildManagement.BuildProcessLauncher.AnalyseComponentBuildInExternalProcess(FilePath projectFilePath, BuildXml buildXml, String useBuildConfiguration, String useBuildPlatform, DirectoryPath solutionDir, String solutionName, List`1 importExpressionsToEvaluate, ProcessorArchitecture processorArchitecture, VisualStudioVersion vsVersion, IList`1 customEnvironmentVariables)
at nCrunch.Client.ComponentLoader.SnapshotComponentFactory.(ProcessorArchitecture )
at nCrunch.Client.ComponentLoader.SnapshotComponentFactory.CreateSnapshotComponentFromXml(FilePath projectFilePath, BuildXml projectXml, FilePath solutionFilePath, String[] additionalFilesToIncludeAtSolutionLevel, Boolean isLoadedFromFile, ISnapshotConfig snapshotConfig, VisualStudioVersion vsVersion)

Hi, thanks for sharing this issue.

When NCrunch searches for MSBuild under VS2013, it looks for the following assembly in your GAC:

Microsoft.Build, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL

If the assembly cannot be found, NCrunch will throw this error.

It's my understanding that under VS2013, this assembly should normally be registered in your GAC. Can you check whether it exists? If the VS installer didn't register it, you may need to do so manually using Gacutil.exe