Thanks folks. I upgraded to latest BP and issue was solved 
Hello everyone!
First of all, thank you for your responses. The problem is now solved. However, I don’t know how! I wrote to the web host describing the problem and to the best of my guess, they changed few PHP.INI settings [Don’t know how it got messed?]
The system did not have bbpress. I’ve upgraded buddypress to latest stable and everything seems to be working fine now.
To answer the questions :-
1. Are you running WPMU 2.7.1 or WordPress 2.8? You mention that you were running WPMU before. Did you upgrade to the beta version of WPMU 2.8 from trunk? Or, did you accidentally upgrade to WP 2.8? WPMU 2.8 is not yet in public release.
-> I did not upgrade accidently. In fact, one of the members reported that there was an error. The system was running fine with WPMU 2.7.1 and BP 1.0 (the first stable release) and then suddenly the error popped up.
2. What other plugins besides BP do you have activated? Have you tried removing them all except BP and see if you can get back to the plugins page?
-> I do not have any other plugin than BP.
3. Have you tried removing BP and then seeing if the plugins page returns? If it does, then deactivate all other plugins and reinstall BP. What happens?
-> No, I didn’t try that. I could not deactivate any plugins, because I couldn’t see the plugins in the admin panel!
From the overall experience, it looks like the issue was with me signing in as site-admin but ending up in blog admin panel (anyone knows why this happened?)
On that particular install, all I did was remove everything from the bbPress folder except the bp-config. Then I pasted everything from the new version of bbPress in there and it just went crazy. LOL It started off with a wp-header error which I figured out & fixed (can’t remember how) but then this error came up about not being able to open the core signup page so I just started over.
@TheEasyButton
Did this behavior occur after installing the bbPress Integration plugin? Or, was it some other aspect of the overall bbPress integration?
Did you recently upgrade bbPress? That was the exact error I got the other day when doing the bbPress upgrade. It made absolutely zero sense to me because the file was obviously there. It also deleted all abilities to see plugins & BuddyPress in admin. I know you said you didn’t do any upgrades or tweaks but maybe this one didn’t come to mind.
I agree with Burt. My three questions and suggestions were going to be this:
- Are you running WPMU 2.7.1 or WordPress 2.8? You mention that you were running WPMU before. Did you upgrade to the beta version of WPMU 2.8 from trunk? Or, did you accidentally upgrade to WP 2.8? WPMU 2.8 is not yet in public release.
- What other plugins besides BP do you have activated? Have you tried removing them all except BP and see if you can get back to the plugins page?
- Have you tried removing BP and then seeing if the plugins page returns? If it does, then deactivate all other plugins and reinstall BP. What happens?
Someone reporting email issues with groups as well: https://buddypress.org/forums/topic.php?id=3183
I wonder if the messaging system uses cookies?
It doesn’t sound really like the issue the 3 of us found. Does it? I just got finished working with somebody yesterday. His problem was that creating one group after another on the same computer caused the 2nd group to adopt the group id of the 1st group.
The underlying issue and solution was that he didn’t have any cookie domains set in wp-config.php
https://buddypress.org/forums/topic.php?id=3452
These cookie issues are tough to debug. We do the ‘works for me’ thing because our wpmu instances are different. Right now bp relies on the wpmu instance supplying the cookie path and domain. Perhaps to cover such situations bp should specify it’s path and domain. Would that bypass the wpmu credentials? Would it matter?
Here we go again. Burt, Jeff, man your battle stations.
We’ll take a look at it.
Right now on testbp.org it looks like it’s working correctly. Was this an upgrade from a previous BuddyPress install, and if so, did you upgrade your member theme files also?
Basically the cause is that Firefox 3.5 has issues with shorthand font declarations that contain quotation marks. Deleting the quotes around the font names will help Firefox cooperate, however it may have negative impacts on older browsers that rely on them.
You can also split up the shorthand and use font-family: Lucida, Tahoma, serif as an example as well.
Hmm… Something isn’t working correctly, because it still says “BP_PLUGIN_DIR” in the error message. Not saying this couldn’t be related to BuddyPress somehow, but it doesn’t sound like it.
Have you installed any other plugins recently? Can you FTP to your plugins directory and disable them one by one and see what happens?
I have got user integration to work fine (wpmu 2.7.1, bp 1.0.2, bbpress 1.0) but see the same problem you describe above with the Attention Admin message when creating groups in bp. Cannot get topic posts to work from within bp either.
q1. do i need the buddypress enable.php activated?
q2. what settings do i have to make for xml-rpc?
I think I’m one step closer now:
I verified, when I log in as a normal user, I don’t see wordpress version in the bottom of admin panel.
So in my current status, I’m NOT getting logged in as an administrator!
Can anyone tell me how do I login as an admin? {PS: I’m not a novice, and have performed admin functions many times. However, I think I’m forcefully being logged in as a non-admin even when I enter admin credentials}
Update:
I tried to edit a user from the admin panel – and I get message “You do not have permission to edit this user”.
Now, how can I be so sure that I’m logged in as site admin and not ‘blog’ admin?
Yes burt, I’m logged in as a site-admin. Using the same username and password that I used for site admin. Don’t know what’s going wrong with me today.
Are you logging in as site admin?
“I can’t see plugins option in the admin panel even if I’m logged in as an admin.”
There’s a diff between a blog admin and the site admin.
This is really strange 
. I overwrote all the wordpress installation files but still don’t see the ‘plugins’ option in the admin panel.
Also, even though the default theme is there, I can only see the default buddypress theme in ‘active’ theme. Other installed themes are not available.
“Buddypres” option is also missing from the left sidebar of admin panel.
Hello Burt, very good to see your response.
Did you rename the buddypress directory? You can’t
=> no, I didn’t.
Is bp active sitewide in the plugins page?
=> I can’t see plugins option in the admin panel even if I’m logged in as an admin.
No, I didn’t do anything. I got a call from one of the members that the site’s showing some error message.
Adding to the observations above, I can’t see the various themes installed as well.
Right now, I’m overwriting my wpmu files with 2.7.1 and see if I see the ‘Plugins’ menu in the admin panel.
I’m keeping the config.php file intact.
Did you rename the buddypress directory? You can’t.
Is bp active sitewide in the plugins page?
That’s pretty scary. Good luck.
Buddypress directories are all there. i checked. I’ve reinstalled WPMU and now backing up buddypress folders before installing the latest version of buddypress.. No I didn’t perform any upgrades/tweaks recently. They were done in past and the site ran fine for weeks before this nasty error appeared.
Sounds like your buddypress directories aren’t there. Can you ftp into the site and see buddypress in your plugins directory under “wp-content”?
Have you done any recent administration on the site? Major changes, minor tweaks?
Update: There’s no buddypress option menu in the admin panel. I’m logged in as admin!
