Login to MySQL: mysql -u your_user -p Then run: USE your_discuz_db; # My DB name is ultrax. SHOW TABLE STATUS WHERE Comment LIKE ‘%crashed%’; In my case, I can see 3 tables crashed. The output confirms that the key Discuz tables (pre_forum_post, pre_forum_sofa, and pre_forum_thread) are badly corrupted. Step-by-Step Recovery with myisamchk Because myisamchk works on raw table files, MySQL must not be running: sudo systemctl stop…