Message Oracle ORA-34177 - (MXCHGDCL19) number cannot be deleted because one or more partitioned variables instantiate it.

ERROR(MXCHGDCL19) number cannot be deleted because one or more partitioned variables instantiate it.
CAUSEUser attempted to CHGDFN DELETE a partition template, but some partitioned variable had data in the partition specified for deletion.
ACTIONDrop the partitions that are causing the problem, then retry.