Do you have other plugins installed that rely on BuddyPress being there? Maybe an early version of the BuddyBar, or something else? If there’s a plugin installed that requires a BuddyPress function to exist, and it doesn’t check appropriately for it being missing, you’ll experience this.
Just had a chance to see this Trace, glad you were able to get it resolved.
http://buddypress.pastebin.com/f6116b6e2
Just realised that it may not be a good idea using the array_shifts at the end, in case the array only contains one element. C’est la vie!
Oops… trunk of course! it’s been a long day… got it working the old fashioned way 
The other point I was making though is that this is linked off the main installation instructions:
https://codex.buddypress.org/getting-started/installing-buddypress/.
The reason I probably didn’t even look at the URL is because of that. I’m sure lots of people will do the same, and if they are new to buddypress they won’t be aware of the usual way of installing it and either post questions here or maybe even give up!
I restored database from two days ago to see if that fixed the issue and it did… no clue what changed in the interim…
Haven’t touched themes… I edited original post above… it looks as though there’s actually zero buddypress code being loaded in sub-domain headers… hence no buddy bar…. so that’s the problem, the buddybar is merely a symtom….
Erm, it’s working on my hosted blogs. No immediate ideas. Have you changed/upgraded the themes the member blog(s) have used?
Since you had single-user WordPress installed before, I’d suggest doing a clean install. This means making sure that you delete both the single-user WP and the newly installed WPMU files. Also, delete your MySQL database and start with a new one.
I assume that you do not have any data yet. If that is correct, then you can safely proceed down this road. If you do have important data in the MySQL DB, then you should back it up first.
Also, you should use a separate MySQL DB for WPMU. Do not use the one that you are already using for single-user WP.
Follow these instructions for help on installing WPMU. Make sure you read through all instructions linked below before beginning the install:
- Download BuddyPress from here
- https://codex.buddypress.org/getting-started/installing-wordpress-mu/
- Read the readme.txt file that comes with the WPMU download
Then, once WPMU is installed and functioning properly, follow these instructions for help on installing BuddyPress.
- https://codex.buddypress.org/getting-started/installing-buddypress/
- Read the readme.txt file that comes with the BuddyPress download
You would edit profile fields like this via /wp-admin/admin.php?page=buddypress/bp-xprofile.php on your installation, but it looks like you can’t add a description for the default Name theme (which you can’t edit or remove).
Nice catch. Report it as an enhancement suggestion on https://trac.buddypress.org/; use your username and password from this site to log in.
And before you ask, no, it is not recommended to use the trunk version of BuddyPress on a public website.
Will I risk having to have the whole thing redone at every update?
Yes – because you’ll essentially be customising the default BuddyPress themes.
*When* does that error appear? After you’ve tried to activate BuddyPress sitewide?
1: 2.8.2 version
2: Directory
3: Root
4: No
5: Yes it works
6: I try to run 1.0.3
7: No
8: No
9: Can´t install it
10: No
11: I not running bbpress
12: -.-
13: Warning: require(/wp-content/plugins/buddypress/bp-core-catchuri.php) [function.require]: failed to open stream: No such file or directory in /wp-content/plugins/buddypress/bp-core.php on line 25
Fatal error: require() [function.require]: Failed opening required ‘/wp-content/plugins/buddypress/bp-core-catchuri.php’ (include_path=’.:/usr/share/php5/’) in /wp-content/plugins/buddypress/bp-core.php on line 25
Luc-
Many people have asked the same question. The good news is that there are plans to make BuddyPress compatible with single-user WordPress in the future.
We’re not sure when that will happen, so give it time and keep checking back.
We have no idea what the issue is now so we cannot provide help. Please provide details.
Read this for more information on asking for support.
If you can build a WordPress theme, building a BuddyPress theme is not very hard – it is just larger.
Here is my first Buddypress-run site: ecofuture.
Runs on MU 2.8.2, BuddyPress 1.0.2, bbPress 1.0.
I was afraid of upgrading to 1.0.3 after reading through the forums and after finally getting the three-way integration to work.
Buddypress pages are worked up fromt he skeleton theme. Homepage blog is based on the Thematic Theme. I got the two to closely resemble each other.
Automattic have got back to me which is great as I had a feeling they might not even respond unless my email address ended with @microsoft.com etc 
Good to know they are at least replying to us smaller companies!
I have to install WordPress MU in the root directory because I want that a domain point to the buddypress blog (/community), so I got the same error. If I install WordPress MU in a folder all works fine but then the visitors see the right url (/net/wp) and not the domain. Could it be that this is a buddypress bug?
@ajonesma
What do you use for the events section?
I’ll be honest to say that I have seen 1and1 home hosting packages in a shared environment hosting BuddyPress with 250+ users without any gripes from anyone. That’s like less than $10 a month btw, but don’t expect ludicrous speed or anything.
Does the link work with the regular bphome theme? This facebook 1.0 theme may need updating for the latest version of BuddyPress.
Something else you could try would be to copy functions.php from bphome and overwrite the file in facebook 1.0 theme.
It looks like you are trying to install BuddyPress under single-user WordPress.
BP currently requires the multi-user version of WordPress. Read this and follow the link in point one: https://codex.buddypress.org/getting-started/installing-buddypress/
