thinktecture/Thinktecture.IdentityServer.v3.EntityFramework — pull request #29 by jerackista (2014-12-26 23:04:22+00:00)
Title: Expand SaveChanged to contain more detailed data when DbEntityValidationException occurs 

Solution taken from here.
http://stackoverflow.com/questions/15820505/dbentityvalidationexception-how-can-i-easily-tell-what-caused-the-error