I updated wp tonight and immediately got this message, which now appears whenever I enter my domain name http://www.learnhangul.com
Fatal error: Call to undefined function wp_get_current_user() in /home/learnhan/public_html/wp-includes/capabilities.php on line 1286
I am unable to access http://www.learnhangul.com/wp-admin
I have a backup plugin, backupwordpress, installed. When I typed in learnhangul.com/wp-content/backups, it takes me to this error page:
I am also unable to enter the cpanel via my hosting service.
What can I do? Any help is much appreciated as I fear I have just deleted several years worth of content!
The last backup I have found on my computer is from July 2011, when the site was only in its infancy, and I fear I have lost basically everything.