not able to kill bpbkar on netbackup client side

I am using netbackup trying to take client backup which remains stuck without writing any data for more than 45 min

Also i am unable to kill "bpbkar.

I checked VSS on client machine which gives me   State: [5] Waiting for completion.

Whats the solution over this?? the technote will be preferred.

my NBU version is 7.1.

need solution