Also, sometimes even creating a new post fails… No error messages, just… nothing.
Sorry for the bump… None of my users are able to reply….
Change to bp-default theme and deactivate all plugins except BuddyPress. You might also want to check out and post at theme’s support forums http://themekraft.com/support/
I am having same issues. I did not deactivate my plugins. I only switched to BuddyPress Default and everything works fine. So it is definitely an issue with the Themes not plugin conflict.
This started since the last upgrade
You’ll need to upgrade your theme @gossyomega1
I have downgraded my buddypress Install to see if thats where the problem lies, however it still persists. I am not running Buddypress 1.2.8 however the reply doesnt work.
So i presume this has to do with the WordPress aspect.
Everything works fine in the default theme however.
I downgraded wordpress with my backup before the upgrade and voila. Everything works perfect again 
If anyone else is having this problem… I narrowed down the plugin that was causing at least my issues… It was ‘Custom Contact Forms’… Sad.
@mercime thanks. please how do i go about this? I am just seeing your reply. I appreciate.
I have the same problem. I have disabled all plugins and changed themes. I have the latest version of bp-columns but I get the non-reply problem with that or the default theme.
The page refreshes, the reply box appears for a fraction of a second and then disappears. Can anyone help, please?
Change to bp-default theme. I believe @modemlooper will be updating bp-columns theme come BP 1.3
TIP: never upgrade on a live site, always test on a separate install before so you don’t break your site until plugins and themes are made compatible. #BrokenRecord
I usually do not upgrade my plugins or themes until a major . Update. will fix any issues when 1.3 drops
Thank you – however, I have changed to the default theme and the problem is the same. I don’t think it is the theme that is causing the problem.
Deactivate all plugins- more than likely it’s a plugin thats creating a query conflict.
I deactivated all plugins. Nothing seems to change the problem. The reply box does appear very briefly and then disappears.
In case it’s any kind of clue, the text typed in the update box stays there after an update has been posted – it didn’t do that before either.
When I upgraded to 1.2.9, I experienced this same issue… I just discovered it from my upgrade to 1.5 bleeding… it’s appears to be a theme issue for sure…. I can disable all of my plugins/bp-custom.php and I still have this issue with my current theme…. when I switch to the default theme, the problem disappears…
So to recap… for me, not a plugin or custom.php issue, but a theme issue AND I am experiencing this in current stable of BuddyPress… I’ve asked @sbrajesh to look at this as I’m using his themes….
Just some more info to this.
Ok, so the issue was resolved by upgrading to the latest BP-Pro Mag theme… Here is my question for the “know-how-to-do-its”… If this is a jquery/theme issue, then what files must be replaced on the theme to make it work correct… I think if you post the answer here, people will find it and fix the problem themselves…
I’ve read this same problem being asked multiple ways on the site and there is no explanation of what to fix other than to “have the theme updated”… is it just a matter of swapping out jquery files? If so which ones? If something additional, what then?
Thanks and hope the coming answer(s) will help someone.
So how does this explain why it’s not working on this site then either? 
I have to go to the last page of a post to find this box. If you click ‘New Reply’ above it does NOTHING on the Buddypress.org site itself … *le sigh*
p.s. The “edit” post link is broken as well…
