Can't access to Admin after upgrading to WordPress 3.8

Hi, I updated my blog to WordPress 3.8 but after that I can no longer access to Admin Panel.

If I try to go to http://www.windowsteca.net/wp-admin I am redirected to http://www.windowsteca.net/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F and I get the following text:

There is no need for any upgrade

Your WordPress database is already up to date!

See here: http://www.windowsteca.net/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F

If I click on Continue the blog’s homepage were shown …

I upgraded to WordPress 3.8 two other blogs hosted in the same server without any problem … And I used the standard atomatic procedure for upgrading in all cases.

I tried to rename the plugins and themes folder via FTP but the problem persists.

Pleas help me.