The Nolics.ORMapper which is providing the support for Sitefinity 3 database connections doesn`t support SQL Server 2012 as it is a retired project now. Even Sitefinity4 dond`t have support for SQL Server 2012 untiull the ORM Sitefinity4 is using called OpenAcess started support for SQL Server 2012 in the first release of OpenAccess for 2012 in january, untill then there was no support for SQL server 2012.
the Telerik team
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