Re: Buddypress Total-Black-Out :(
Also, and this may be a repeat suggestion, but when upgrading, you’re going to want to BACKUP and DELETE the old files, all of them EXCEPT your wp-config.php file. That file you do NOT delete and keep where it belongs.
1. Upload WPMU, visit wp-admin, and make sure it’s running the way it should be.
2. Upload BuddyPress per the install instructions, visit wp-admin, make sure it’s running the way it should be.
3. Reinstall plugins and custom themes.
The reason for the delete is because of all the file locations and names that have changed around since RC1. If you have copies of old files lying around, say in mu-plugins, etc… That will gum things up too.