title: Exception raised when I'm trying enable migrations in EF 4.3.1
body: <p>I'm using Entity framework 4.3.1 installed by nuget in my .Net 4.0 class library project. In situation, when I call the "Enable-Migrations" command in PM console, I receive following exception:</p>
  
  <blockquote>
    <p>Exception calling "LoadFrom" with "1" argument(s): "Nelze načíst soubor nebo sestavení file:///D:\
    Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.4.3.1\to
    ols\EntityFramework.PowerShell.Utility.dll nebo jeden z jejich závislých prvků. Systém nemůže nalé
    zt uvedený soubor."
    At D:\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5.
    0.0-rc\tools\EntityFramework.psm1:393 char:62
    +     $utilityAssembly = [System.Reflection.Assembly]::LoadFrom &lt;&lt;&lt;&lt; ((Join-Path $toolsPath Entity
    Framework.PowerShell.Utility.dll))
       + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
       + FullyQualifiedErrorId : DotNetMethodException</p>
    
    <p>You cannot call a method on a null-valued expression.
    At D:\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5.
    0.0-rc\tools\EntityFramework.psm1:394 char:50
    +     $dispatcher = $utilityAssembly.CreateInstance &lt;&lt;&lt;&lt; (
       + CategoryInfo          : InvalidOperation: (CreateInstance:String) [], RuntimeException
       + FullyQualifiedErrorId : InvokeMethodOnNull</p>
    
    <p>Exception calling "CreateInstanceFrom" with "8" argument(s): "Typ System.Data.Entity.Migrations.En
    ableMigrationsCommand ze sestavení EntityFramework.PowerShell, Version=4.3.1.0, Culture=neutral, P
    ublicKeyToken=b77a5c561934e089 nelze načíst."
    At D:\Users\DvoracekR\Documents\Visual Studio 2010\Projects\WebCameras\packages\EntityFramework.5.
    0.0-rc\tools\EntityFramework.psm1:418 char:31>+     $domain.CreateInstanceFrom &lt;&lt;&lt;&lt; (
       + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
       + FullyQualifiedErrorId : DotNetMethodException</p>
  </blockquote>