Locked out of blog that is down after installing buddypress plugin

2.9.1, actually. Upgraded today before installing some buddypress plugins.

Too many changes at once–guilty as charged.
After installing a buddypress plugin, this is what I get:

“Fatal error: Call to undefined function get_blog_option() in /home/dakineda/public_html/enlightenedhorsemanship/wp-content/plugins/buddypress/bp-core.php on line 566”
Can’t get in–what to do?

http://www.enlightenedhorsemanship.net