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.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.vote_num_minus, 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 category regexp '[[:<:]](1)[[:>:]]' AND SUBSTRING_INDEX( SUBSTRING_INDEX( xfields, 'genre|', -1 ) , '||', 1 ) LIKE '%Mystery%' AND approve=1 AND date < '2021-10-28 07:20:58' AND ( xfields LIKE '%||player|%' OR xfields LIKE '%||player2|%' ) ORDER BY fixed desc, date DESC LIMIT 0,48