Oracle Message ORA-19602 - cannot backup or copy active file in NOARCHIVELOG mode

ERRORcannot backup or copy active file in NOARCHIVELOG mode
CAUSEYou tried to copy or backup a file that was not closed cleanly, and the database was in NOARCHIVELOG mode. This is not allowed because when restored, the file will require redo application before it is usable, and redo is not currently being saved beyond the contents of the online redo logs.
ACTIONTake the tablespace offline clean or close the database and retry the copy or backup.