MySQL error in file: /engine/modules/show.short.php at line 64

Error Number: 3685

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

SQL query:

SELECT p.title_pl, p.short_story_pl, p.full_story_pl, p.id, p.autor, p.date, p.short_story, CHAR_LENGTH(p.full_story) as full_story, p.xfields, p.title, p.category, p.alt_name, p.comm_num, p.allow_comm, p.fixed, p.tags, e.news_read, e.allow_rate, e.rating, e.vote_num, e.votes, e.view_edit, e.editdate, e.editor, e.reason FROM dle_post p LEFT JOIN dle_post_extras e ON (p.id=e.news_id) WHERE ( (title_pl <> '' AND short_story_pl <> '' AND title_pl <> '' AND short_story_pl <> '') OR ( xfields LIKE '%hide_for_language|No%' ) ) AND category regexp '[[:<:]](66)[[:>:]]' AND approve=1 ORDER BY fixed desc, news_read DESC LIMIT 0,35