Did you by any chance change $table_prefix in wp-config.php as part of the upgrade? If so there are SQL updates within the options table in the database that need to be made.
I get this error message :
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Downloading update from http://wordpress.org/wordpress-2.7.1.zip
Unpacking the core update
Verifying the unpacked files
Installing the latest version
Warning: copy(/home/kansirneta/domains/kansir.com/public_html/wordpress/wp-blog-header.php) [function.copy]: failed to open stream: Permission denied in /home/kansirneta/domains/kansir.com/public_html/wordpress/wp-admin/includes/class-wp-filesystem-direct.php on line 122
Warning: copy(/home/kansirneta/domains/kansir.com/public_html/wordpress/wp-blog-header.php) [function.copy]: failed to open stream: Permission denied in /home/kansirneta/domains/kansir.com/public_html/wordpress/wp-admin/includes/class-wp-filesystem-direct.php on line 122
Could not copy file: /home/kansirneta/domains/kansir.com/public_html/wordpress/wp-blog-header.php
Installation Failed
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How to fix it ?
No stvwlf I did not. If it helps I also cannot use the install new plugin feature either.
I worked out out thanks to this post
Here is the solution in a nutshell.
I went to wp-admin/options.php
Changed the db version to the last version I had installed (8204)
It then forced a database upgrade and fixed the problem!
Simple solution to a pain in the butt problem!