Hello,
What version of SEP are you running?
Are you running SEP 11.0.5002 or above??
Could you try following steps -
1. Stop Symantec Embedded Database service
2. Delete sem5.log from the location indicated in logs
3. Start Symantec Embedded Database service
If the Above steps does not help, do you have a backup of the SEPM database??
If yes, please perform a Disaster Recovery steps - http://www.symantec.com/docs/TECH102333
Hope that helps!!