My b2evolution Version: Not Entered

I receive the following error after the installer tells me everything is successful:

Fatal error: Cannot instantiate non-existent class: usersettings in /data03/zante/public_html/blog/inc/_main.inc.php on line 207

Obviously I'm quite nervous as my site is popular and now it's down. Should I try to get the new version working or just stick with my old one forever?

Install log:

Upgrading data in existing b2evolution database...
Loading: _core/model/__core.install.php
Loading: sessions/model/_sessions.install.php

Checking DB schema version... 9700 : OK.
Upgrading blogs table... OK.
Upgrading items table... OK.
Creating keyphrase table... OK.
Upgrading hitlog table... OK.
Upgrading sessions table... OK.
Creating goal tracking table... OK.
Creating DB schema version checkpoint at 9800... OK. (Elapsed upgrade time: 1 seconds)
Updating keyphrases in hitlog table... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OK.
Upgrading widgets table... OK.
Upgrading Files table... OK.
Creating DB schema version checkpoint at 9900... OK. (Elapsed upgrade time: 1 seconds)
Upgrading Blogs table... OK.
Adding new Post Types...OK.
Updating User tableOK.
Creating table for User field definitionsOK.
Creating default field definitions...OK.
Creating table for User fields...OK.
Creating DB schema version checkpoint at 9910... OK. (Elapsed upgrade time: 1 seconds)
Upgrading Posts table... OK.
Upgrading Categories table... OK.
Upgrading widgets table... OK.
Updating item types...OK.
OK.
Updating items table...OK.
Creating versions table...OK.
Updating group permissions...OK.
Creating DB schema version checkpoint at 9930... OK. (Elapsed upgrade time: 1 seconds)
Updating hitlog table...OK.
Updating versions table...OK.
Altering Blogs table... OK.
Altering default dates... OK.
Altering Items table... OK.
Forcing AutoP posts to html editor...OK.
Creating DB schema version checkpoint at 9950... OK. (Elapsed upgrade time: 2 seconds)
Renaming tables...OK.
Making sure all tables use desired storage ENGINE...T_groups:innodb
T_settings:innodb
T_global__cache:innodb
T_users:innodb
T_users__fielddefs:innodb
T_users__fields:innodb
T_skins__skin:innodb
T_skins__container:innodb
T_blogs:innodb
T_coll_settings:innodb
T_widget:innodb
T_categories:innodb
T_items__item:innodb
T_postcats:innodb
T_comments:innodb
T_locales:innodb
T_antispam:innodb
T_usersettings:innodb
T_items__prerendering:innodb
T_items__version:innodb
T_items__status:innodb
T_items__type:innodb
T_items__tag:innodb
T_items__itemtag:innodb
T_files:innodb
T_subscriptions:innodb
T_coll_user_perms:innodb
T_coll_group_perms:innodb
T_links:innodb
T_filetypes:innodb
T_plugins:innodb
T_pluginsettings:innodb
T_pluginusersettings:innodb
T_pluginevents:innodb
T_cron__task:innodb
T_cron__log:innodb
T_sessions:myisam
T_basedomains:myisam
T_useragents:myisam
T_track__keyphrase:myisam
T_hitlog:myisam
T_track__goal:myisam
T_track__goalhit:myisam
OK.
Creating DB schema version checkpoint at 9960... OK. (Elapsed upgrade time: 3 seconds)
Installing plugin: tinymce_plugin... OK.
Installing plugin: twitter_plugin... OK.

The database schema is up to date.

Upgrade completed successfully!

I'm uploading the new version again to make sure I haven't missed anything.