Site has been working great for a long time. Just saw the upgrade button. Clicked it and then received the following response.
Fatal error: Call to undefined function is_rtl() in /home/wiredtog/public_html/wp-includes/general-template.php on line 2102
Now I can't even log into the /wp-admin.
Totally stuck/hosed. What can I do now?
Note: Not a coder so please be gentle :-)