This error is caused by a newly implemented dependency in SEP RU5 and newer releases. As of RU5 SEP clients will depend on the System Event Notification Service being installed and/or running. It sounds as though this is either not installed or has been disabled on this system.
I would check first to ensure that the service is available. You can check this through the system services (services.msc). If the service is disabled, enable, set to automatic and then start the service. Once started attempt to start the SMC service or reboot the system.
If the System Event Notification Service fails to start this would indicate an issue with the operating system. We do have a workaround available, however the document is not public facing. As such if you would like assistance with performing the workaround for the SEP client please call in and open a case. For your convenience your can reference Document ID 2010050317081348 so the technician can easily locate this in our internal knowledge base.
Regards.