Recently I successfully upgraded to Wordpress Mu version 2.9.1 with Buddypress version 1.2.1. Wordpress MU and Buddypress lacks serious documentation and help is hard to find.  In my first attempt I ended with 404 errors on any link I click after the upgrade. In another attempt I my site up and running but the links to Blogs, Members and Forums would get redirected to the home page.

After lots of trial and error, and spending almost a day finally I found a solution.

1. Disable all wordpress plugins, buddypress plugins.

2. Change the active theme to any non buddypress theme. This way site is not clean of any legacy buddypress items.

3. Upgrade to the latest version of buddypress. Do not activate it yet.

3. Delete “bp-default” and “bp-sn-parent” from the themes directory.

4. Activate Buddypress. Select buddypress default theme.

At this point my upgrade was complete but I kept getting 404 errors on any link I click.

To resolve this issue create a new .htaccess file in the wordpress installation root directory and copy/paste following code

RewriteEngine On
RewriteBase /

#uploaded files
RewriteRule ^(.*/)?files/$ index.php [L]
RewriteCond %{REQUEST_URI} !.*wp-content/plugins.*
RewriteRule ^(.*/)?files/(.*) wp-content/blogs.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteCond %{REQUEST_URI} ^.*/wp-admin$
RewriteRule ^(.+)$ $1/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule . – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-.*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

<IfModule mod_security.c>
<Files async-upload.php>
SecFilterEngine Off
SecFilterScanPOST Off
</Files>
</IfModule>

After this bingo my buddypress is working like a charm.

I am hoping that with this post I hope I would be able to save lot people from grief.