How to fix SQL Error 1054 - Unknown column

[Mark]

I'd just upgraded to MyBB version 1.6, and everything was running smoothly until i started cleaning up my plugins, in the process i removed my old 1.4 prefix plugin as 1.6 has its own support.

Then i tried to browse categories and just received;

Code:

MyBB SQL Error

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
1054 - Unknown column 't.prefix' in 'on clause'
Query
SELECT t.*, p.displaystyle AS threadprefix, ((t.totalratings/t.numratings) AS averagerating, r.uid AS rated, t.username, u.username FROM mybb_threads t LEFT JOIN mybb_users u ON (u.uid = t.uid) LEFT JOIN mybb_threadratings r ON(r.tid=t.tid AND r.uid='1') LEFT JOIN mybb_threadprefixes p ON (p.pid = t.prefix) WHERE t.fid='28' AND (t.visible='1' or t.visible='0') ORDER BY t.sticky DESC, t.lastpost desc, LIMIT 0, 20

Which is bad.

Looking through the database using phpmyadmin, i couldn't find the culprit.

Fix:

Re-upload the /install/ directory in to the root (public_html) of your website. Then browse to http://yourwebsite.com/install/upgrade.php and re-upgrade your forum. This'll reload the tables and clean up any crap.

Once finished, delete the /install/ directory and carry on as usual.