If you’ve got access to your error logs, take a look at them to see what’s happening.
Otherwise, upload a fresh copy of the index.php to start with.
If it still doesn’t work, then check your wp-config.php for any erroneous characters. If you’re unsure what to look for, just open the wp-config-sample.php that comes with downloads of WordPress (http://wordpress.org/download/) and fill in all the appropriate database details, then upload it to replace the wp-config.php you’ve got on your website (make sure you keep a copy, just in case).
If still no joy, delete the wp-admin and wp-includes folders and re-upload those too, along with all the files in the main WordPress directory (except for the wp-config.php that you’ll have already uploaded earlier).
And if still no luck… temporarily rename your plugins directory (wp-content/plugins) to something else, just in case you’ve got a rogue plugin causing the problem.
Should be enough to be going on with…
Anyhow, once you get back into your Admin, you’ll find the version number at the bottom of the screen. If it’s not the current version (2.8.4 at the moment), then upgrade!!
No luck. I tried to upgrade manually as well. Nothing loads 🙁
You could try resetting the plugins folder by phpMyAdmin. Sometime’s it’s the only way to get rid of a really stubborn plugin.
Or assume it’s a hack:
http://wordpress.org/support/topic/268083#post-1065779
I tried to restore everything and that seemed to resolve the issue. The same thing happened again…
My hosting provider said that the index.php file was modified but I haven’t done anything for this to happen.
These can be signs of a hacked site.
Crap. Ill check out that thread esmi. Thank you all for your help. One last thing. If I delete my wordpress files will I lose all my content? Or does it save in my database?