OCI-59615
Oracle ADVM volume files of Oracle ASM file group '%0!s' cannot be deleted using the DROP FILEGROUP command with the CASCADE option
Cause
An attempt was made to drop cascade an Oracle Automatic Storage Management (Oracle ASM) file group that still contains files in it. File groups associated to a volume should not be cascade dropped.
Action
Drop the volume files by dropping the volume. If the files are not part of any volume and were moved into this file group, drop the files before dropping the file group.