Oracle Message ORA-12031 - cannot use primary key columns from materialized view log on string.string

ERRORcannot use primary key columns from materialized view log on string.string
CAUSEThe materialized view log either did not have primary key columns logged, or the timestamp associated with the primary key columns was more recent than the last refresh time.
ACTIONA complete refresh is required before the next fast refresh. Add primary key columns to the materialized view log, if required.