Upgrade to 3.8.6 went bad...
 

I'm upgrading to 3.8.6 in preparation for upgrading to version 4.

I get this error in the admin panel:

Invalid SQL:

SELECT COUNT(*) AS count
FROM moderation AS moderation
INNER JOIN post AS post USING (postid)
WHERE moderation.type='reply';

MySQL Error : Unknown column 'postid' in 'from clause'
Error Number : 1054

I think that I misfollowed the instructions and I ended up with two forum folder on the server. The old one is called "forum" and the new one is called "forums". Oh dear.