it was my first post, so I am sorry for not writing those information.
1. Which version of WP/MU are you running? 3.1
2. Did you install WP/MU as a directory or subdomain install? directory
3. If a directory install, is it in root or in a subdirectory?subdirectory
4. Did you upgraded from a previous version of WP/MU? If so, from which version? yes, upgraded but don’t remember which one was before 3.1
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? Version 1.2.8
7. Did you upgraded from a previous version of BP? If so, from which version? yes, dont remember which one was before 1.2.8
8. Do you have any plugins other than BuddyPress installed and activated? If so, which ones?
yes : Bad Behavior,BP-Album+,BP-NotificationWidget,BP My Home,BP Profile Search,BP Redirect to Profile for Buddypress,BP Show Friends,BP Xtra Signup,BuddyPress,BuddyPress Activity Stream Bar,BuddyPress for WP e-Commerce,BuddyPress Like,BuddyPress Links,BuddyPress Moderation,BuddyPress Privacy Component (BP Privacy, BP_Authz, or BPAz),Invite Anyone,Jet Event System for BuddyPress,RS Buddypress Activity Refresh,Use Google Libraries,W3 Total Cache
9. Are you using the standard BuddyPress themes or customized themes? – it is the default one but I changed it
10. Have you modified the core files in any way? – no
11. Do you have any custom functions in bp-custom.php? -no
12. If running bbPress, which version? Or did your BuddyPress install come with a copy of bbPress built-in? -no
13. Please provide a list of any errors in your server’s log files. – Nope, shared server
14. Which company provides your hosting? – Godaddy
15. Is your server running Windows, or if Linux; Apache, nginx or something else? I think Linux
I fixed this problem. W3 Total Cache was causing this problem
