My website: http://www.davidaldridgeofficial.com
An error message had appeared on my site over the weekend just gone. I was updating my site and it froze, so I closed it and re opened and this message appeared.
"Fatal error: Call to undefined function is_multisite() in /home/content/45/4961745/html/wp-includes/wp-db.php on line 505"
I am unsure how to proceed, not having a real computer brain doesn't help!
I cannot find a way to even log in so any help would be great. The site is work related so its important I get it running ASAP.