MySQL error in file: /engine/modules/show.full.php at line 1250

Error Number: 3685

The Error returned was:
Illegal argument to a regular expression.

SQL query:

SELECT id, date, short_story, xfields, title, category, alt_name, tags REGEXP '[[:<:]]()[[:>:]]' as score FROM if_post WHERE tags REGEXP '[[:<:]]()[[:>:]]' AND id != 98 AND approve=1 ORDER BY score DESC LIMIT 20