Hi,
Thank you for posting in Symantec community.
I would be glad to answer your query.
Are you attempting to register the SNAC license before the SNAC component is enabled/installed on the SEPM will result in a licensing error? Check the following KB for more details.
Installing SNAC 12.1 in conjunction with an existing installation of Symantec Endpoint Protection Manager (SEPM) 12.1
http://www.symantec.com/docs/TECH168055