I attempted to upgrade using the InstantUpgrade plugin and something has gone wrong (fortunately, I backed up the database and all of my folders/files).
Currently on my blog, I get the error:
Fatal error: Call to undefined function add_action() in /home/gibbscom/public_html/yepyep/wp-includes/functions.php on line 28
My site is http://yepyep.gibbs12.com
Any idea what is causing this? I've tried re-installing files in wp-includes but that has not worked.