To solve this problem, please to the steps bellow:
1. Go to database directory(ex. C:\Program Files (x86)\Symantec\Symantec Endpoint Protection
Manager\db) and remove everything besides sem5.db file.
2. Open command line and navigate to %ProgramFiles%\Symantec\Symantec Endpoint Protection
Manager\ASA\win32.
3. Run command:
dbsrv11 -f"C:\Program Files\Symantec\Symantec Endpoint Protection Manager\db\sem5.db"
3. Start Symantec Embedded Database.
4. Run dbisqlc from "C:\Program Files (x86)\Symantec\Symantec Endpoint Protection
Manager\ASA\win32". and log into Database like in the picture.
5. Run query DROP INDEX I_SEM_AGENT_COMPUTER_ID_PLUS
Afer this procedure, you should be able to use SEPManager with no issue.
Second option:-
How to perform Disaster Recovery without Database backup/Restore