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.