Cloud Storage backup to Amazon S3

Hi,

    I've a windows 2008 R2 MAster Server and a Linux Media Server. All are running Netbackup 7.5.0.7 (upgraded recently from 7.1.0.4). I'm trying to setup the Cloud Storage Backup option but failed with the attached message. 

P.S. I've setup successfuly in a test envronment the same account

Thanks,