I have downloaded and tried this around 10 times with the same result.

I have downloaded both the WP files only and the entire pack of files, just in case there was an issue with one of the zip files, and nothing.

I also tried uploading the file through the WP admin panel and I get an error saying ‘Are you sure you want to do this?’ and try again, which just takes me back to reupload the theme.

Any chance that the file at ThemeForest is corrupt? All of the other themes work fine.