RMAN-05173
Pluggable databases will not be opened as some are in an invalid state.
Cause
ALTER PLUGGABLE DATABASE ALL OPEN could not be performed as some PDBs were created during recovery. Because of this, their datafiles were offlined and they cannot be opened.
Action
Additional messages will state which PDBs are in an unopenable state. Either restore and recover their datafiles or drop them in order to be able to perform alter pluggable database all open for the valid PDBs.