Thanks Anthony, I’ve tried that already.
I’ve tried everything suggested here:
==========
– switching to the Twenty Eleven theme by renaming your current theme’s folder in wp-content/themes using FTP or whatever file management application your host provides.
– resetting the plugins folder by FTP or phpMyAdmin.
– re-uploading all files & folders – except the wp-content folder – from a fresh download of WordPress.
– re-running the upgrade manually using wp-admin/upgrade.php.”
==========