Well, we really don’t have enough information about your environment to specifically offer assistance. Here are a few questions to get this started:
- Which version of Lighty are you running?
- Which version of WPMU are you running?
- Did you install WPMU as a directory or subdomain install?
- If a directory install, is it in root or in a subdirectory
- Was WPMU functioning properly before installing BuddyPress?
- What permalink structure do you have setup in WPMU?
- Which version of BuddyPress (BP) are you running?
- Please provide a list of any errors in your server’s log files.
Also, how much experience do you have with installing and configuring Lighty? I ask this because I’m guessing that your issue is more than likely a server configuration issue having to do with permalink rewriting.
Was WPMU functioning properly before you tried installing and activating BuddyPress? In other words, could you create posts? Did they show up on the default WPMU theme? Could you navigate to them when clicking on their link? Did you receive any errors? You should not attempt to install BuddyPress until your WPMU setup is functioning perfectly.
People successfully run WPMU on LightTPD and Nginx web serving platforms. These two platforms do not support, do not use, .htaccess files. They cannot use .htaccess files. But, they can be configured to properly rewrite permalinks. The .htaccess file is not essential, not required, for WPMU to run properly. What is required is a facility to rewrite permalinks.
Sorry for not providing enough info, here it is:
1. Latest version of lighty for Debian Lenny, 1.4.19-5
2. WPMU trunk (as of last night)
3. Subdomain install
4. NA
5. Working fine, using rewrites from here: http://is.gd/11Izw
6. /blog/%year%/%monthnum%/%postname%/
7. Trunk (as of last night)
8. No errors to report, just a PHP error that it couldn’t load the GD library; not relevant methinks.
WPMU was functioning fine, I made sure it was before trying to install BP. Post creation, viewing etc all normal.
I’m on Slicehost and this is my first experience of running a server from scratch; but I’m picking things up quickly and this is the first big issue.
Okay, several more questions?
Did you manually install BuddyPress or use WPMU’s plugin browser to install BP?
Did you restart the web server after making changes to the rewrite rules in the configuration file?
In your OP, you state that you have moved the bphome theme into /wp-content/themes/. Did you also move bpmember into /wp-content/bp-themes/?
Also, look near the bottom of this installing WPMU codex article for suggestions on Lighty rewrite rules: https://codex.wordpress.org/Installing_WPMU
* I manually installed the BP files
* I restarted the webserver after making the rewrite changes
* I also moved the bpmember theme to the correct location
* Lighty rewrite rules are working fine, the rewrites I’m using are basically the same
I can install other plugins in the wp-content/plugins directory, it’s just buddypress not showing up. Same with other themes.
Thanks for helping out 
Just so we can say we tried this:
- Please delete BuddyPress from the plugins folder. You can keep the bphome and bpmember themes in their proper places.
- Then deactivate all other plugin
- Log out of WPMU and clear your browser’s cache
- Redownload BuddyPress
- Remove the themes folder from the download as it is not needed–you already have the themes installed (we’ll assume for now that they are in good shape)
- Upload BuddyPress to /wp-content/plugins/
- Optional Step: Go outside and turn in a counterclockwise circle three time. Circumference of circle is not relevant.
- Fire up WPMU, log in as site admin and go to the plugins menu
- If it is visible, try activating it sitewide
Let me know what happens
Fantastic! Can’t believe I didn’t try this already but after deleting the buddypress files and re-uploading everything is in working order!
Must have been a dodgy upload perhaps? Either way, thanks so much for helping me with this. You’re time’s really appreciated. 
Spoke too soon…
Although the bphome theme and the plugins are all working correctly, I get an error trying to access frontend pages:
You do not have any BuddyPress themes installed.
Please move “/wp-content/plugins/buddypress/bp-themes/” to “/wp-content/bp-themes/” and refresh this page. You can download more themes here.
However, they are definitely installed in /wp-content/bp-themes/ and I’ve re-uploaded multiple times. You can see here:
http://getconcero.org/wp-content/bp-themes/
Any ideas?!
Go into the wp backend Buddypress > General Settings
Select theme to use for BuddyPress generated pages > Buddypress Default Member Theme 1.0.1
Make sure that is selected and Save the settings
Well this is what I get in the list:
WordPress Classic (1.5)
WordPress mu Default (1.6)
WordPress mu Homepage (1.6)
Because I looked there.
Its obviously reading the contents of my wp-content/themes directory, so I tried moving bpmember from bp-themes to wp-content/themes; sure enough it now shows up on the list and I can choose it.
However, I’m still getting the error on user pages. I’ve reverted back to the original setup and still trying to work this out.
The main problem is that BP isn’t recognizing that the folder exists…
Permissions on the /bp-themes dir strange?
Just set it, and the contents, to 777, and no change.
It shows up on the list like that because that’s where bp is looking for it’s themes. In the /wp-content/themes dir. It shouldn’t be. It should be looking in /wp-content/bp-themes.
Do you have any kind if aliasing going on for the dirs?
I’m looking at the code that does the theme hijacking and can’t understand how it’s failing.
The only rewrites I’m using are these: http://is.gd/11Izw
I really don’t get this either… Frustrating as hell!
Well this is what I get in the list:
WordPress Classic (1.5)
WordPress mu Default (1.6)
WordPress mu Homepage (1.6)
Are you sure that you’re looking in the proper spot? The theme list you provided is what you see when you go to “Site admin > Themes”. These are the themes from which you can choose your home theme.
To choose your member theme, you need to go to the BuddyPress menu grouping all the way down at the bottom of the menu column. So, as Burt indicated, you would go to “BuddyPress > General Settings > Select theme to use for BuddyPress generated pages”.
You choose the member theme from the combo box. With a default BP install you should only see two theme choices: BuddyPress Default Member Theme (1.0.1)–this is the one you want–and, Skeleton BuddyPress Member Theme (1.2).
Are you saying that instead of those two themes showing up in the “BuddyPress > General Settings” menu area that you have the home themes you’ve listed above?
I had a related problem which I resolved temporarily by renaming the ‘bpmember’ directory in wp-content/bp-themes to ‘default’:
https://buddypress.org/forums/topic.php?id=2835#post-17511
What is your install configuration like honewatson?
I’ve just reinstalled Mu 2.7.1 and Buddypress 1.01 again and this time I can select the bpmember theme from within Mu Admin under Buddypress settings. However, I cannot post from any buddypress field. Every buddypress post action seems to be undefined as wp_explain_nonce is being called.
I can still perform any post action with WordPress Mu.
@honewatson, I’m glad that you have things up and running to that point. I was trying to determine if you and hempsworth have any configuration or host properties in common. What I was looking for is:
Web server
PHP version
Subdirectory or subdomain for wpmu
FYI my PHP version is 5.2.6-1, it’s a fresh VPS so I’m installing the latest stable of everything.
I might try backing my current config up and starting from scratch again… It might work, but if theres a solution I’d rather not do all of that again!
Should I go from the current stable versions for each of the installs? WPMU 2.7.1, BP 1.0.1 and bbPress 1.0 RC2? I’ve always used trunk for each but I’ll do stable this time?
Usually the current stable is probably best? I tried for a few hours to integrate bbPress 1.0 trunk last night and something appeared broken in it (could be my brain that’s broken too.)
The issues you describe are pretty strange, and new ones compared to most. When re-installing, do me a favor and delete your cookies for your site also; lets make this as clean of an installation as possible.
@jacoby – I experienced similar cookie issues with brain broken and the trunk – got it working by deleting cookiepath and hash and deleting existing cookies- https://bbpress.org/forums/topic/cookie-integration-problem-wp28-bb-10-rc-2 but since this is about lighttpd I’m sure that hempworth’s problem is the lack of mod_rewrite and this may help – https://mu.wordpress.org/forums/topic/1961
@honewatson
As Burt has requested, we would like to see if there are any commonalities between your issue and Hempsworth’s issue. Web server (Apache, Lighty, Nginx), version of PHP, and WPMU install method (subdirectory or subdomain) would help us narrow this down a bit.
@Windhamdavid
Actually Hempsworth must have mod_rewrite installed and loaded as his Lighty config file is properly rewriting his WPMU URLs. WPMU is functioning for him and since doing a clean reinstall of BuddyPress, he was able to activate it.
But now he has a different issue–a strange missing-theme files issue.
@Hempsworth
Did you see my question here In this post?
Are you saying that instead of those two themes showing up in the "BuddyPress > General Settings" menu area that you have the home themes you've listed above?
Since there is now an assumption that you are having the same issue as honewatson has described, we need an answer. Until then, we should not assume that the two issues are related.
