مشکل در ادد مایگریشن

سلام استاد خسته نباشید 

بنده در جلسه 21  property  (Tags) رو به model Page اضافه کردم بعد که خواستم migration بزنم با ارور زیر مواجه شدم لطفا راهنمایی کنید 

با تشکر از شما. 

PM> Add-Migration Add_Tags_Pages

Exception calling "LoadFrom" with "1" argument(s): "Could not load file or assembly 'file:///C:\Users\Zand\Desktop\MVC\MyCms\packages\EntityFr

amework.6.4.4\tools\EntityFramework.PowerShell.Utility.dll' or one of its dependencies. The system cannot find the file specified."

At C:\Users\Zand\Desktop\MVC\MyCms\packages\EntityFramework.6.2.0\tools\EntityFramework.psm1:782 char:5

+     $utilityAssembly = [System.Reflection.Assembly]::LoadFrom((Join-P ...

+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException

   + FullyQualifiedErrorId : FileNotFoundException

You cannot call a method on a null-valued expression.

At C:\Users\Zand\Desktop\MVC\MyCms\packages\EntityFramework.6.2.0\tools\EntityFramework.psm1:783 char:5

+     $dispatcher = $utilityAssembly.CreateInstance(

+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   + CategoryInfo          : InvalidOperation: (:) [], RuntimeException

   + FullyQualifiedErrorId : InvokeMethodOnNull

Exception calling "CreateInstanceFrom" with "8" argument(s): "Could not load file or assembly 'file:///C:\Users\Zand\Desktop\MVC\MyCms\package

s\EntityFramework.6.4.4\tools\EntityFramework.PowerShell.dll' or one of its dependencies. The system cannot find the file specified."

At C:\Users\Zand\Desktop\MVC\MyCms\packages\EntityFramework.6.2.0\tools\EntityFramework.psm1:811 char:5

+     $domain.CreateInstanceFrom(

+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~

   + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException

   + FullyQualifiedErrorId : FileNotFoundException