I have followed the upgrading instructions http://ellislab.com/expressionengine/user-guide/installation/update_build.html
and then these ones as well: http://ellislab.com/expressionengine/user-guide/installation/update.html
Front-end is working fine.
I get the following error when trying to access the backend:
A Database Error Occurred
Error Number: 1054
Unknown column ‘show_sidebar’ in ‘field list’
SELECT `m`.`username`, `m`.`screen_name`, `m`.`member_id`, `m`.`email`, `m`.`url`, `m`.`location`, `m`.`join_date`, `m`.`last_visit`, `m`.`last_activity`, `m`.`total_entries`, `m`.`total_comments`, `m`.`total_forum_posts`, `m`.`total_forum_topics`, `m`.`last_forum_post_date`, `m`.`language`, `m`.`timezone`, `m`.`daylight_savings`, `m`.`time_format`, `m`.`profile_theme`, `m`.`forum_theme`, `m`.`private_messages`, `m`.`accept_messages`, `m`.`last_view_bulletins`, `m`.`last_bulletin_date`, `m`.`display_signatures`, `m`.`display_avatars`, `m`.`parse_smileys`, `m`.`last_email_date`, `m`.`notify_by_default`, `m`.`ignore_list`, `m`.`crypt_key`, `m`.`cp_theme`, `m`.`quick_links`, `m`.`quick_tabs`, `m`.`template_size`, `show_sidebar`, `g`.* FROM (`exp_members` m, `exp_member_groups` g) WHERE `g`.`site_id` = ‘1’ AND `unique_id` = ‘047dbe39962f392bbb3dae028e267d49ae38c86b’ AND `password` = ‘5b947e69c3effcfd215a1d0a24fefa7af70098e7’ AND m.group_id = g.group_id
Filename: libraries/Session.php
Line Number: 494