This is Database corruption problem. Follow the steps to repair database from Telnet Console:
1. Select option 5 Cyberoam Management
2. Select option 4 Database Utilities
3. Select option 1 Database Quick Repair
If problem persists even after repairing database then log on to Web Admin Console and purge Web Surfing logs from System > Manage Data > Purge Logs. After purging logs, restart management services from Telnet Console.