title: Assembly could not be installed because existing policy would keep it from being used
body: <p>While attempting to load an earlier version of a .NET assembly, indicated as possible in a comment on an answer to <a href="https://stackoverflow.com/questions/10502543/mssql-2012-creating-clr-triggers-for-wcf-fails">MSSQL 2012 creating CLR triggers for WCF fails</a>. I receive the titular error message.</p>
  
  <p>Despite searching for additional information on the error itself, ensuring that 3.5 was installed in Windows Features, investigating useLegacyV2RuntimeActivationPolicy and more, I have been unable to determine how to enable previous versions of .NET assemblies to execute in SQL Server 2012 on Server 2012.</p>
  
  <p>Does anyone know what is required to allow this execution?</p>