Thread:Project:Support desk/Blank/empty upgrade page when upgrading from 1.15.1

I'm running MediaWiki 1.15.1 and am trying to upgrade to 1.22.

I do not have shell access (shared server) so I have to upload files via FTP. I did this with no errors, and I tried to pull up /mw-config/index.php but the page as well as the home page were just empty/blank pages.

MySQL version5.5.34-cll PHP version5.4.21

I'm a little confused by this and looked for an answer but didn't find anything helpful. What might the problem be?