Help: PBS pro install in a single node

Hi, everyone.
I am install pbs pro in ubuntu 18.04 in a single node.
I have come across this error when I tried to start the pbs server.
$ sudo /etc/init.d/pbs start
Starting PBS
/opt/pbs/sbin/pbs_comm ready (pid=26546), Proxy Name:localhost:17001, Threads:4
PBS comm
PBS mom
PBS sched
/opt/pbs/sbin/pbs_ds_systemd: 43: [: xdegraded: unexpected operator
Connecting to PBS dataservice…connected to PBS dataservice@localhost
PBS server

#And When I type
$ /etc/init.d/pbs status
pbs_server is not running
pbs_mom is pid 26575
pbs_sched is not running
pbs_comm is not running

Could you suggest what might be the problem?
Thank you.

Wishes,
Jiaqi

please check the logs in pbs home. Default location is /var/spool/pbs/server_logs/…