I have recently realised that after installing Visual Studio 2012 RC all the projects containing the edmx file fails to compile with the following message:
– Encountered an error hydrating the EDMX file
– Could not load file or assembly ‘Microsoft.Data.Tools.Schema.Sql, Version=188.8.131.52, Culture=neutral, PublicKeyToken=c15f5f6t12e50a1a’ or one of its dependencies. The system cannot find the file specified.
I have seen people talking about removing all Visual Studio versions and do a clean install which simply wasn’t acceptable to me so I found my answer on the Microsoft connect page
This issue is caused by installing a pre-release version of Visual Studio 2012 on top of Visual Studio 11 Developer Preview as stated by “Entity Framework Team”
– close all Visual Studio instances
– delete the file C:\Program Files (x86)\MSBuild\4.0\Microsoft.Common.targets\ImportAfterMicrosoft.Data.Tools.Integration.targets
– open the solution in your favourite VS and try again.
It did work for me