BuddyPress.org

I tried to upgrade to 1.11 and I faced this problem

Fatal error: Cannot redeclare bp_activity_install() (previously declared in /home2/travelq0/public_html/wp-content/plugins/buddypress/bp-activity.php:19) in /home2/travelq0/public_html/wp-content/plugins/buddypress/bp-activity.php on line 52

So what do I need to do?

and now my page has an error even if I tried to deactivate bp

Fatal error: Call to undefined function bp_is_blog_page() in /home2/travelq0/public_html/wp-content/themes/thesis_151/header.php on line 24