錯誤日志
升級到Unity2018之后，使用 Open C# Project 打開VS工程，出現報錯，無法啟動VS。
錯誤日志如下：
ArgumentException: Value does not fall within the expected range.
SyntaxTree.VisualStudio.Unity.Bridge.CompilationUnit.LanguageOf (SyntaxTree.VisualStudio.Unity.Bridge.CompilationUnit unit)
SyntaxTree.VisualStudio.Unity.Bridge.CompilationUnit.CompilationUnits (System.String method)
SyntaxTree.VisualStudio.Unity.Bridge.CompilationUnit.CompilationUnits ()
SyntaxTree.VisualStudio.Unity.Bridge.ProjectSystem.UnitySolutionBuilder..ctor ()
SyntaxTree.VisualStudio.Unity.Bridge.ProjectSystem.UnitySolutionBuilder.CreateSolutionFromAssetDatabase ()
SyntaxTree.VisualStudio.Unity.Bridge.ProjectFilesGenerator.GenerateProject ()
SyntaxTree.VisualStudio.Unity.Bridge.ProjectFilePostprocessor.OnPreGeneratingCSProjectFiles ()
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.AssetPostprocessingInternal.OnPreGeneratingCSProjectFiles () (at C:/buildslave/unity/build/Editor/Mono/AssetPostprocessor.cs:194)
UnityEditor.VisualStudioIntegration.SolutionSynchronizer.Sync () (at C:/buildslave/unity/build/Editor/Mono/VisualStudioIntegration/SolutionSynchronizer.cs:207)
UnityEditor.SyncVS.SyncSolution () (at C:/buildslave/unity/build/Editor/Mono/SyncProject.cs:190)
UnityEditor.SyncVS.SyncAndOpenSolution () (at C:/buildslave/unity/build/Editor/Mono/SyncProje
Unity Down Assistant
在Unity的Download Assistant中進行下載VS組件
vs_Enterprise安裝Unity組件
在vs_Enterprise.exe 中安裝unity的組件也是失敗
其它排查方法
懷疑是Unity的問題，重新安裝 Unity，問題無法解決。
更換其它版本的unity，比如2018.2.9f1，問題無法解決。
解決方案
如果是VS2015，則可以通過下載新版本的Visual Studio Tools For Unity 進行更新。（公司機器測試通過）
如果是VS2013，下載新版本的Visual Studio Tools For Unity 更新后也是失敗（家里機器）。
更新VS2017，問題得到解決。