Oracle Message RMAN-05528 - datafile number not processed because file belongs to tablespace with one or more offline immediate datafile (string)

ERRORdatafile number not processed because file belongs to tablespace with one or more offline immediate datafile (string)
CAUSEA DUPLICATE command omitted processing the indicated datafile because it is part of a tablespace that has offline immediate datafile. See message 5526.
ACTIONNo action is required. This is an informational message only.