how to resolve “InnoDB: Error (Duplicate key) writing word node to FTS auxiliary index table” in mysql

I am continuous getting above error in mysqld log. Please tell me what is this error about and how to solve it. I am using mysql 5.7 (not mariadb)

A guess: A FULLTEXT index on that table is corrupted.

ALTER TABLE tablename ENGINE=InnoDB;

should rebuild the FT index, thereby fixing the problem.

If that is not sufficient, please provide SHOW CREATE TABLE; there may be some other clues there.