Insuffiient privileges

I had a huge system issue with my  iMac requirng a re installof my OS… Now  my Passort is denying  me access because Ihave “insufficient  priviliges”

 Ive tried  chmod 775 “/Volumes/volumename/”   and  also

  sudo chown root:admin /Volumes/“volume name”

Press RETURN. Enter your admin password when prompted.

killall Finder


 but  no  joy…

 any  ideas here?

 I note that  in “get info” one of the users  is system… I ve never seenthat  before

reading  another  thread…maybe her eis a clue… I updated the software and  firmware  before this problem became evident

It  has been suggested that  installing the previous  firmware might  reset the  drive to allow access… question is…“where do I get it  from?”  emailed WD  for an answer

I’m not a Mac user. They had a problem a while ago with the firmware updates On Mac  Check some of this and the solution in post 47 I don’t know if it applies to you or not.