Upgrade Help

I upgraded my version of wp and Im having this problem.
I can’t write a post or even see my posts.
This is the error I get

Fatal error: Call to undefined function get_shortcode_regex() in /home/raven/public_html/viddlesandbits.com/wp-includes/formatting.php on line 95

I tried searching the forums and reuploaded the files like the posts I found suggested and it didn’t help.
Can someone please help me.

Bevvy
http://viddlesandbits.com