BuddyPress.org

1. Which version of WP/MU are you running?
2.9.2
2. Did you install WP/MU as a directory or subdomain install?
Directory on local server
3. If a directory install, is it in root or in a subdirectory?
Root
4. Did you upgraded from a previous version of WP/MU? If so, from which version?
No, fresh install
5. Was WP/MU functioning properly before installing/upgrading BuddyPress (BP)? e.g. permalinks, creating a new post, commenting.
Yes
6. Which version of BP are you running?
1.2.3
7. Did you upgraded from a previous version of BP? If so, from which version?
No, fresh install
8. Do you have any plugins other than BuddyPress installed and activated?
No
9. Are you using the standard BuddyPress themes or customized themes?
I am not using, with WP classic template when BuddyPress is activated I can’t log in
10. Have you modified the core files in any way?
No
11. Do you have any custom functions in bp-custom.php?
I didn’t change anything
12. If running bbPress, which version? Or did your BuddyPress install come with a copy of bbPress built-in?
Hm…
13. Please provide a list of any errors in your server’s log files.
Here u are: https://mu.wordpress.org/forums/topic/17904?replies=5
14. Which company provides your hosting?
ovh.pl