I got this really weird general error trying to edit an old post.
Can't copy/paste, so I'm retyping it here. What I got was:
=================================
General Error
SQL ERROR [mysqli]
Incorrect key file for table './phpbb3/gamers_posts.MYI'; try to repair it [126]
SQL
(A lot of text here from what I was trying to update)
BACKTRACE
File: includes/db/mysqli.php
Line: 163
Call: dbal->sql_error()
File: includes/functions_posting.php
Line: 1960
Call: dbal_mysqli->sql_query()
File: posting.php
Line: 1001
Call: submit_post()
==========================
Hope this helps