First of all you are are experimenting on the version that is end of support 3 years ago, if its a prodcution servers you need to get this server upgraded to support as soon as its stable.
regarding the issue, what are that exact steps followed to change the IP address
can you give the output of below commands
bpclntcmd -ip <old IP address>
bpclntcmd -ip <new IP address>
bpclntcmd -hn <master server name>
ping <old IP address>
ping <new ip address>
Do this master server has any media servers connected or its standalone master server?
On the backup server run:
ipconfig /flusddns and the Netbackup command bpclntcmd -clear_host_cache
Then restart Netbackup.
Please also verify forward name lookup works e.g:
nsloookup "name of your server"
AND reserve name lookup works - e.g
nslookup "IP addresse of server".
Both forward and reverse name lookup should match with the new IP. if not there is a mismatch in the configuration and Netbackup will have problem in starting.
If reserve name lookup is a issue, you can disable Netbackup reverse name lookup's by running