MySQL error in file: /engine/api/api.class.php at line 362

Error Number: 3685

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

SQL query:

Select * from dle_post where (category regexp "[[:<:]](171)[[:>:]]") AND approve = 1 AND date < "2024-04-26 13:50:16" AND id != 6531 AND id < 6531 order by id DESC limit 0,20