[jackofallvices]

1. Which version of WordPress are you running?

4.3.1

2. Did you install WordPress as a directory or subdomain install?

root directory

3. If a directory install, is it in root or in a subdirectory?

root

4. Did you upgrade from a previous version of WordPress? If so, from which version?

4.3

5. Was WordPress functioning properly before installing/upgrading BuddyPress (BP)? e.g. permalinks, creating a new post, commenting.

yes

6. Which version of BP are you running?

2.3.3 (also with 2.5.8 bbpress)

7. Did you upgraded from a previous version of BP? If so, from which version?

no

8. Do you have any plugins other than BuddyPress installed and activated? If so, which ones?

yes

AG Custom Admin
All In One WP Security
bbPress
bbPress Multi Image Uploader
bbPress Notices
BuddyPress
BuddyPress Forum Editor
Bug Library
Coming soon and Maintenance mode WpDevArt
Content Aware Sidebars
GD bbPress Tools
Merge + Minify + Refresh
Redis Object Cache (currently deactivated and troubleshooting)
Remove Dashboard Access
rtMedia for WordPress, BuddyPress and bbPress
Scrollbar Designer
Steam News Widget
WP Change Default From Email
WP Clone by WP Academy
WP Super Cache
WP ULike
WPS Hide Login

9. Are you using the standard WordPress theme or customized theme?

child of Spacious from themegrill

10. Have you modified the core files in any way?

a couple small tweaks in child theme

11. Do you have any custom functions in bp-custom.php?

not that i am aware of

12. If running bbPress, which version? Or did your BuddyPress install come with a copy of bbPress built-in?

yes, 2.5.8

13. Please provide a list of any errors in your server’s log files.

[Wed Sep 16 11:20:01.065681 2015] [fcgid:warn] [pid 19091] [client my.ip.address:1024] mod_fcgid: stderr: PHP Notice:  Undefined offset: 0 in /home/mysite/public_html/wp-content/plugins/bbpress/includes/extend/buddypress/functions.php on line 133, referer: http://mysite.com/groups/united-division/forum/
[Wed Sep 16 11:20:01.065720 2015] [fcgid:warn] [pid 19091] [client my.ip.address:1024] mod_fcgid: stderr: PHP Notice:  Trying to get property of non-object in /home/mysite/public_html/wp-content/plugins/bbpress/includes/extend/buddypress/functions.php on line 133, referer: http://mysite.com/groups/united-division/forum/

14. Which company provides your hosting?

Self hosted Debian Jessie with virtualmin

15. Is your server running Windows, or if Linux; Apache, nginx or something else?

Debian Jessie

I have debugging on and when I go to a locked thread in a group forum (open or private so far), the same error is displayed on top as part of wp debug

[16-Sep-2015 18:21:55 UTC] PHP Notice:  Undefined offset: 0 in /home/mysite/public_html/wp-content/plugins/bbpress/includes/extend/buddypress/functions.php on line 133
[16-Sep-2015 18:21:55 UTC] PHP Notice:  Trying to get property of non-object in /home/mysite/public_html/wp-content/plugins/bbpress/includes/extend/buddypress/functions.php on line 133

My site is currently locked down for beta testers. I could give you the address in private but I would need your IP address to whitelist you.

[shanebp]

bbPress has it’s own support forums.

As you probably know, PHP notices are not that critical.
You might try looking at the file in the notice.
I suggest you review the function and perhaps add a conditional to check if topic is empty before adding to $new_title
You may have found a bug. You can create a ticket here.