Entity framework Code First 迁移 Migrations

PM> Enable-Migrations
使用“8”个参数调用“CreateInstanceFrom”时发生异常:“未能加载文件或程序集“EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089”或它的某一
个依赖项。系统找不到指定的文件。”
所在位置 C:\Users\Administrator\Desktop\MvcApplication1\packages\EntityFramework.5.0.0\tools\EntityFramework.psm1:431 字符: 31

• $domain.CreateInstanceFrom <<<< (
• CategoryInfo : NotSpecified: (:) [], MethodInvocationException
• FullyQualifiedErrorId : DotNetMethodTargetInvocation

用 nuget装下EntityFramework 5.0
Install-Package EntityFramework -Version 5.0.0