wp-admin/upgrade – blank page

I have deleted wordpress 2.3.3 and uploaded 2.5. When I went to wp-admin/upgrade.php, it goes to a blank page, and when I logged in, it also brings me to a blank page with the following url: https://www.everdestiny.com/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F

I have deleted all plugins, and themes in case of incompatibility, but still to no avail.

Can someone assist me with this?