Here's what I get when I try and update anything in admin...
A Database Error Occurred
Error Number: 1054
Unknown column 'used' in 'where clause'
UPDATE `exp_security_hashes` SET `used` = 1 WHERE `used` = 0 AND `hash` = '746210f63c79d55cea1189dff211bcd41e498ccd' AND `session_id` = '34720b679f2886c6fd3e45071c2f9a20482f4a53' AND `date` > 1378217984
Filename: core/EE_Security.php
Line Number: 169
Just tried upgrading from 2.6.1 to 2.7