Hello, i was trying to install OpManager, but it was failed to install. See below i whenever i run the Installation Script to install OpManager i got the following error

[root@ns1 bin]# ./StartOpManagerServer.sh
/opt/ManageEngine/OpManager/bin/..
/opt/ManageEngine/OpManager/bin/..
Exception in thread " main"  java.net.UnknownHostException: ns1.example.com: ns1.example.com: Name or service not known
    at java.net.InetAddress.getLocalHost(Unknown Source)
    at com.adventnet.ncm.util.NCMServerUtil.findoutAddressList(NCMServerUtil.java:321)
    at com.adventnet.ncm.util.NCMServerUtil.getAllServerInetAddresses(NCMServerUtil.java:294)
    at com.adventnet.ncm.util.NCMPortChecker.getInstance(NCMPortChecker.java:62)
    at com.adventnet.ncm.util.NCMPortChecker.main(NCMPortChecker.java:215)
Caused by: java.net.UnknownHostException: ns1.example.com: Name or service not known
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
    at java.net.InetAddress$1.lookupAllHostAddr(Unknown Source)
    at java.net.InetAddress.getAddressesFromNameService(Unknown Source)
    ... 5 more
./StartOpManagerServer.sh: line 16: syntax error near unexpected token `done' 
./StartOpManagerServer.sh: line 16: `done'