I'm just saying that you're never going to solve the problem with this limited information. Okay, so the upgrade.php is blank. That does not help us. You have to try other things.
If you have to keep the site online at all costs, then guess what, don't upgrade it. Make a backup of the site and try to upgrade that. Do something else. Find somebody who can do it and get them to do it for you if necessary. Or whatever, my point is that the cycle of upgrade-doesn't work-rollback is pointless and futile. Doing the same thing repeatedly when you know it does not work is the definition of insanity.
This forum is a support forum, we can only help those who help themselves. If you're just a user, if you have no technical knowledge at all, if you cannot try something else and give us feedback on the results, then we cannot help you. All we can do is make suggestions, but there's nothing for us to make a suggestion on here.
Try the wp-pro mailing list. Maybe somebody there can do it for you.