This past weekend, we performed (with 3rd party help) an Oracle 10g to Oracle 11g upgrade. Process took a while but was to be expected. Overall, everything works great except for daily backup job of the Oracle database. We use "EVault" which is a cloud backup solution. Our Oracle server is a physical server. Our backups were working fine before the upgrade, no blips, errorts, etc. They just work seamlessly! First attempt of backup produced error, ORA-12577. We've looked at this and we know it is some sort of TNS Adapater protocol error but we just can't figure it out. We've changed the "PATH" entry in environment variables but still no luck. Made a registry change, which by the way, still shows a Oracle 10g branch within the registry. Should that actually go away or does it always stay now? There is a new branch for 11g there, but thought it was odd that 10g still sitting in there. Any help on this would be fully appreciated.