Hi Sanket i followed the steps bellow: http://www.postgresqltutorial.com/postgresql-restore-database/
I also tried with pgsql and pg_restore didn't get any error. i then changed to a lower version of PGADMIN3 1.18 still didn't get any error. i then built the new version 1.22.0 Alpha 2 from the git repository. this also has no error. i guess the problem is limited to only pgAdmin III Version 1.20.0. Kind regards, Byaruhanga Franklin