could not load type 'system.data.entity.design.aspnet.entitydesignerbuildprovider'
Open your web.config and add this line below in the Assemblies section:
<add assembly="System.Data.Entity.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />For more information, check this link:
http://forums.asp.net/t/1698282.aspx
Hope this helps
Adding to @wandos answer, here is the layout for web.config:
<system.web> <compilation debug="true" targetFramework="4.5"> <assemblies> <add assembly="System.Data.Entity.Design, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" /> </assemblies> </compilation> <httpRuntime targetFramework="4.5" /> </system.web>