Not to hi-jack your post but I'm having a similar issue.
Updated from admin panel, entire site is blank, I have error messages they might help.

In the log i have;
Undefined index: host File: /home/xxxxxxx/public_html/xxxxx/ow_core/request.php Line:214

Then when I try to visit any page on my site in the browser I get;
Undefined index: host File: /home/xxxxxxx/public_html/xxxxx/ow_core/request.php Line:214

Can anyone help?

Same problem here 

Topic was moved from Installation Troubleshooter and Server setup.

I knew I wasn't the only one with errors

Guys, did you update platform first and then plugins? 
Have you enabled debug mode to catch the actual error. Please do if not. 

Josh, please do not duplicate your posts. 

Suspend the Update until the problem gets locked down or there will be a lot of users posting the same thing soon.

I get this when attempting to upgrade from 1.8.0 to 1.8.1:

[Tue Jan 12 22:46:43 2016] [ow_core_log] [Exception] Message: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'key' in 'where clause' File: /var/www/example.com/public_html/ow_core/database.php Line:723 Trace: [#0 /var/www/example.com/public_html/ow_core/database.php(723): PDOStatement->execute() | #1 /var/www/example.com/public_html/ow_core/database.php(308): OW_Database->execute('SELECT * FROM o...', Array) | #2 /var/www/example.com/public_html/ow_core/base_dao.php(114): OW_Database->queryForObject('SELECT * FROM o...', 'BOL_Theme', Array, 86400, Array) | #3 /var/www/example.com/public_html/ow_system_plugins/base/bol/theme_dao.php(111): OW_BaseDao->findObjectByExample(Object(OW_Example), 86400, Array) | #4 /var/www/example.com/public_html/ow_system_plugins/base/bol/theme_service.php(485): BOL_ThemeDao->findByKey('simplicity') | #5 /var/www/example.com/public_html/ow_core/theme_manager.php(86): BOL_ThemeService->getThemeObjectByKey('simplicity', false) | #6 /var/www/example.com/public_html/ow_core/application.php(174): OW_ThemeManager->initDefaultTheme() | #7 /var/www/example.com/public_html/index.php(54): OW_Application->init() | #8 {main}]

same error i got

Bryan, the update has not been successfully completed you need to run the update again. 

See this post: http://www.oxwall.org/forum/topic/44215?page=1#post-170986