Exceptions happen in a part of network management function after modifying the operating system time
Shut down the network management system and database system and restart operating system of server, the problem is solved.
Set the correct system time in when network management system is installed. Don’t modify the operating system time of server when system is running. Only you modify the time after you shutting down the network management system.
Modify the operating system time when network management system is running, exceptions may happen in some functions based on timer, e.g. timing dump of operation log.