MySQL error in file: /engine/modules/show.full.php at line 986

Error Number: 1139

The Error returned was:
Got error 'invalid character class' from regexp

SQL query:

SELECT id, date, short_story, xfields, title, category, alt_name FROM dle_post WHERE category regexp '[[:<:]]([)[[:>:]]' AND MATCH (title, short_story, full_story, xfields) AGAINST (' {') AND id != 327 AND approve=1 AND date < '2023-06-07 04:57:17' LIMIT 8