Can't start counterparty-server

I try to start couterpaty-server , but can’t start.

What I did was…

$counterparty-server bootstrap
$counterparty-server start

accorting to tutorial.

but the server answered like below…

[INFO] Running v1.1.1 of counterparty-server. 
[INFO] Running v9.51.3 of counterparty-lib. 
[INFO] Acquiring lock. 
[INFO] Connecting to database. 
[INFO] Connecting to backend. 
[INFO] Starting API Server. 
[INFO] Resuming parsing. 
Killed

even though once in ten times… it moved correctly…

What is the problem?

※ I use Ubuntu14.04.

Can it connect to back end Bitcoin Core? Is Bitcoin Core running? Is it btcdrak’s addrindex version?

Edit: you mentioned it moves correctly once in 10 times.
Assuming Bitcoin Core is btcdrak’s build with addrindex patch:
a) It could be that Bitcoin Core is having stability problems or can’t keep up. When you tail debug.log, do you see frequent errors? Is Bitcoin Core up to date most of time?
b) In Counterparty server configuration parameters. Are you using minrelaytxfee and other values as per https://github.com/CounterpartyXCP/counterparty-lib?
c) Did you install Bitcoin Core manually (with Python pip) or using the Federated Node install script? Manual installations are error prone.

When you start counterparty-server, you could tail Bitcoin Core log and also try to run bitcoin-cli commands to make sure that Bitcoin Core is working properly. I haven’t seen a situation where Counterparty server fails to work when Bitcoin Core is correctly functioning.