drupal_send_headers

Dunno if you're having the same problem that I was having, but this is what fixed it for me:

diff --git includes/common.inc includes/common.inc
index 12940ab..a6b2a83 100644
--- includes/common.inc
+++ includes/common.inc
@@ -2528,9 +2528,11 @@ function drupal_page_footer() {
   if (variable_get('cache', 0) && ($cache = drupal_page_set_cache())) {
     drupal_serve_page_from_cache($cache);
   }
+  /* Disabling because something calls drupal_page_header() after this point.
   else {
     ob_flush();
   }
+  */
 
   _registry_check_code(REGISTRY_WRITE_LOOKUP_CACHE);
   drupal_cache_system_paths();

#2: common.inc-disable-ob_flush-call-in-drupal_page_footer.patch queued for re-testing.

We will need more information to understand what the bug is here.

One thing that could happen is that something start output before we reached _drupal_bootstrap_page_header(). That can happen for example if your settings.php file starts the output (for example because it has an hidden BOM character), or because a notice is generated before we reach _drupal_bootstrap_configuration() and set the error handler.

@Damien -- thanks once again. Will try to reproduce error with strategically placed debug_backtrace() calls.

Hello, i got this error at the bottom of every page

Warning: Cannot modify header information - headers already sent by (output started at /home/myname/public_html/includes/common.inc:2561) in /home/robbycan/public_html/includes/bootstrap.inc on line 1040

Warning: Cannot modify header information - headers already sent by (output started at /home/myname/public_html/includes/common.inc:2561) in /home/robbycan/public_html/includes/bootstrap.inc on line 1044

the error appear when i login as authenticated user or as admin. It doesn't show up when i'm not log in. I not sure when it start to happen, but it happen after i make the following changes:
1. I put user menu /user login block at header region
2. Stop disqus
but when i cancel all my changes, the error still show up.

thanks

What does "2. Stop disqus" mean and what possible effect could it have on Drupal?

@pillarsdotnet: no 2.Stop disqus means i uninstall disquz module.

Hey.... After uninstall and reinstall all module, the error disappear... :D

I haven't seen this one lately, either.

I had this problem after updating some modules. I solved this by going back to my backup and re-update the modules. The problem is in the code of some update?

I had a similar error message together with a PDO error. I found it was an odd character in a person's name in one of my nodes. Once I found this it fixed the error.

Hi,
Is this save to do: https://drupal.org/files/issues/common.inc-disable-ob_flush-call-in-drup...?

greetings, Martijn

While I'm having a similar issue, I don't think that this might be the best way of going about solving it. It would probably serve better to figure out what is calling ob_flush() and why.