Sql1092n & DB21009E error after upgrading the db2 database from 9.1 to 9.7 ?

I had upgraded DB2 database from version 9.1 FP12 to 9.7 FP4. After the upgrading the users <db2dbsid> & <sidadm> are unable to start db2 database from db2 command prompt. They are not having authorization to execute db2start and db2stop commands.