ISSUE
CAUSE
This error is typically caused by the problem that the SQL database server is currently not working, or it was not running when the DualShield server was starting.
If we check in the Services, then we will find that MySQL service, MySQL(DUAL), may or may not be running
If we check the das6.log file below
C:\Program Files\Deepnet DualShield\tomcat\logs\das6.log
then we should find an event similar to the one below:
RESOLUTION
If MySQL service is running, then restart the Dualshield service.
If MySQL service is not running, then you must restart the MySQL service first. After MySQL service is running again, restart the Dualshield service.