RMAN-08641
for restoring data file string, no suitable image copy or backup set found during backup-based duplicate
Cause
Duplicate operation with 'from datafilecopy', 'from backupset', 'instant sparse', or 'instat sparse only' option was executed when no suitable image copies or backup sets of some data files were available at appropriate locations.
Action
Arrange a suitable image copy or backup set of the data file at appropriate location and re-run the duplicate command.