This property is not available on SQL Server 7.0

You're likely getting this error because you're trying to interface with SQL Server 2012 through the version 10.0 (2008) of the SMO library -- SQL is backwards compatible, not forwards compatible.

Ensure that you are compiling against the version (11.0) 2012 SMO libraries (can be found in the installation SDK directory), and that if you include any SMO libraries with your installation that they are also the version 11.0 binaries.