An email alert is repeatedly sent referencing a virus detection event on a Mac client. The alerts may be identical, except for the database insert time, or they may reference different threats and file locations. The log screen in the SEP client on the Macintosh is empty and the file or path does not exist on the client.
Most likely a corrupt log file. OS X may have been upgraded while SEP was installed, which is not recommended.
Uninstall and reinstall SEP on the affected Macintosh.