Error when installing SQL Management Studio

9 Feb

So another management console installation problem today. This time SQL.

The error I got:
ERROR: Runtime error: This method explicitly uses CAS policy, which has been obsoleted by the .NET Framework. In order to enable CAS policy for compatibility reasons, please use the NetFx40_LegacySecurityPolicy configuration switch. Please see for more information.


  • Backup machine.config, enterprisesec.config, enterprisesec.config.cch, security.config & security.config.cch in C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config
  • Edit C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config
    • Replace <runtime /> with <runtime> <NetFx40_LegacySecurityPolicy enabled=”true”/> </runtime>
  • ¬†Navigate to C:\Windows\Microsoft.NET\Framework64\v2.0.50727
    • Run caspol.exe -all -reset
  • A security.config and security.config.cch will be created in C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config
    • Copy these files to C:\Windows\Microsoft.NET\Framework64\v2.0.50727\Config and C:\Windows\Microsoft.NET\Framework\v2.0.50727\Config
  • Execute SQL Setup
  • Restore original files in C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config

This worked for me.  Let me know if it works for you!


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