Отображение не работает в MVC

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Hello
   i am getting an below error when i am created the readymade create, edit etc views in mvc 
    The name 'EntityState' does not exist in the current context
     Due to this my mapping is not working in mvc. Please give me the solution.
 
This is working when i used System.Data.Entity namespace but my  mapping is not working in mvc

Что я уже пробовал:

Hello
   i am getting an below error when i am created the readymade create, edit etc views in mvc 
    The name 'EntityState' does not exist in the current context
     Due to this my mapping is not working in mvc. Please give me the solution.
 
This is working when i used System.Data.Entity namespace but my  mapping is not working in mvc

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