MSDN on this article says:
CLR uses Code Access Security (CAS) in the .NET Framework, which is no longer supported as a security boundary. A CLR ass
i know that's not a real solution but you can change security mode:
EXEC sp_configure 'show advanced options', 1 RECONFIGURE; EXEC sp_configure 'clr strict security', 0; RECONFIGURE;
This is the easiest solution for those who want to continue their work