title: Visual Studio 2015 Broken Razor Intellisense
body: <p>After installing and then repairing my <strong>VS2015</strong> instance I still cannot get intellisense (server side) to work in my MVC views.
  I get alerted by message prompt as soon as I open for the first time in a session an <em>.cshtml</em> file and get addressed to the Activitylog file.
  Error message retrieved in ActivityLog.xml (short version): </p>
  
  <blockquote>
    <p>System.ArgumentException: Item has already been added. Key in
    dictionary: 'RazorSupportedRuntimeVersion'</p>
  </blockquote>
  
  <p>Here's the full version:</p>
  
  <blockquote>
    <p>System.Reflection.TargetInvocationException: Exception has been thrown
    by the target of an invocation. ---> <strong>System.ArgumentException: Item
    has already been added. Key in dictionary:
    'RazorSupportedRuntimeVersion'</strong> Key being added:
    'RazorSupportedRuntimeVersion' at
    System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean
    add) at System.Collections.Hashtable.Add(Object key, Object value) at
    System.Collections.Specialized.HybridDictionary.Add(Object key, Object
    value) at
    Microsoft.VisualStudio.Utilities.PropertyCollection.AddProperty(Object
    key, Object property) at
    Microsoft.VisualStudio.Html.Package.Razor.RazorVersionDetector.Microsoft.Html.Editor.ContainedLanguage.Razor.Def.IRazorVersionDetector.GetVersion(ITextBuffer
    textBuffer) at
    Microsoft.Html.Editor.ContainedLanguage.Razor.RazorUtility.TryGetRazorVersion(ITextBuffer
    textBuffer, Version&amp; razorVersion) at
    Microsoft.Html.Editor.ContainedLanguage.Razor.RazorErrorTagger..ctor(ITextBuffer
    textBuffer) --- End of inner exception stack trace --- at
    System.RuntimeMethodHandle.InvokeMethod(Object target, Object[]
    arguments, Signature sig, Boolean constructor) at
    System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags
    invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
    at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr,
    Binder binder, Object[] args, CultureInfo culture, Object[]
    activationAttributes, StackCrawlMark&amp; stackMark) at
    System.Activator.CreateInstance(Type type, BindingFlags bindingAttr,
    Binder binder, Object[] args, CultureInfo culture, Object[]
    activationAttributes) at System.Activator.CreateInstance(Type type,
    Object[] args) at
    Microsoft.Html.Editor.ContainedLanguage.Common.ContainedCodeErrorTaggerProvider'1.CreateTagger[T](ITextBuffer
    textBuffer) at
    Microsoft.VisualStudio.Text.Tagging.Implementation.TagAggregator'1.GatherTaggers(ITextBuffer
    textBuffer)</p>
  </blockquote>
  
  <p>If it's any help, I have some font-coloring customizations, and have the Web Essentials, Bundler &amp; Minifier and Web Compiler extensions installed.</p>
  
  <p><strong>UPDATE</strong>: it happens either when I open an existing web application or when I create a brand new one from scratch.
  There's also an instance of <strong>VS2013</strong> installed and running on the same machine.</p>
  
  <p><a href="https://i.stack.imgur.com/W1Waz.jpg"><img src="https://i.stack.imgur.com/W1Waz.jpg" alt="No intellisense at all"></a> </p>
  
  <p>As you can see from the pic above I get no intellisense at all, nor any kind of code coloring.</p>
  
  <p>Any clue about how to fix it?
  Thanks in advance.</p>