dbus[1953]: [system] Connection has not authenticated soon enough, closing it (auth_timeout=30000ms, elapsed: 30000ms)

Recently I found that I was unable to allocate new VNC desktop in my CentOS7 server. After checking the system log, I found that dbus was unable to activate new service. When I used busctl command to list the connetion, it told me that 'Failed to list names: Connection reset by peer'