Use the clr enabled option to specify whether user assemblies can be run by SQL Server. The clr enabled option provides the following values.

WOW64 servers must be restarted before the changes to this setting will take effect. Restart is not required for other server types.

Note:
When RECONFIGURE is run and the run value of the clr enabled option is changed from 1 to 0, all application domains containing user assemblies are immediately unloaded.

Note:
Common language runtime (CLR) execution is not supported under lightweight pooling. Disable one of two options: "clr enabled" or "lightweight pooling. Features that rely upon CLR and that do not work properly in fiber mode include the hierarchy data type, replication, and Policy-Based Management.