ORA-27211 is usually a linking problem, but on windows this usually isn't a problem since the linking is done when NetBackup is installed.If you upgraded NetBackup, did you bounce Oracle? Sometimes Oracle will take NetBackup's orasbt.dll library and ...
Stefan,It's helpful to display the whole RMAN error stack and not just a single error. I've never seen an RMAN error stack with a single error, but there is always a first.If ORA-12557 is the only error, have your Oracle DBA look at Oracle's metalink...