MySQL error in file: /engine/modules/blockpro/block.pro.3.php at line 552

Error Number: 1

The Error returned was:
Can't create/write to file '/var/tmp/#sql_3929_0.MAI' (Errcode: 28)

SQL query:

SELECT p.id, p.autor, p.date, p.short_story, p.full_story, p.xfields, p.title, p.category, p.alt_name, p.allow_comm, p.comm_num, p.fixed, p.tags, e.news_read, e.allow_rate, e.rating, e.vote_num, e.votes from dle_post p LEFT JOIN dle_post_extras e ON (p.id=e.news_id) where approve AND NOT category regexp "[[:<:]](40|41)[[:>:]]" AND MATCH (title, short_story, full_story, xfields) AGAINST ("Cougar loves her stepdaughter Cougar loves her stepdaughter") AND id !=61887 AND date < "2021-05-15 21:23:23" order by RAND() DESC limit 0,24