Warning: Cannot modify header information – headers already sent by (output star

that error states there is a blank line before the opening php statement
there can not be any blank lines after the closing php statement either

I am receiving these and if I could log in to take out the blank lines, great, but I cannot log in I just received the warnings. Can you help me get around the problem so I can post to my page?

Login to your web-host via FTP, or use your host’s backend rather than WP’s to do the edit.

I posted this on another thread with same issue: here goes a solution:
Paste ob_start(); at the TOP of my functions.php file (Was the file generating the error messages)

Solved Issue

I have had my blog up for about 6 months now, however, thanks to some hackers, I have been forced to wipe everything, including the DB and re-install fresh.

I am getting the same “Cannot modify header information…” errors when running the install. This is brand new install, with empty DB.

Adding the ob_start() did not help.

errors from the install login –
Warning: Cannot modify header information – headers already sent by (output started at /home/leeandlo/public_html/blogs/general/wp-includes/default-filters.php:214) in /home/leeandlo/public_html/blogs/general/wp-login.php on line 290

Warning: Cannot modify header information – headers already sent by (output started at /home/leeandlo/public_html/blogs/general/wp-includes/default-filters.php:214) in /home/leeandlo/public_html/blogs/general/wp-login.php on line 302

errors from after entering login information –

Warning: Cannot modify header information – headers already sent by (output started at /home/leeandlo/public_html/blogs/general/wp-includes/default-filters.php:214) in /home/leeandlo/public_html/blogs/general/wp-login.php on line 290

Warning: Cannot modify header information – headers already sent by (output started at /home/leeandlo/public_html/blogs/general/wp-includes/default-filters.php:214) in /home/leeandlo/public_html/blogs/general/wp-login.php on line 302

Warning: Cannot modify header information – headers already sent by (output started at /home/leeandlo/public_html/blogs/general/wp-includes/default-filters.php:214) in /home/leeandlo/public_html/blogs/general/wp-includes/pluggable.php on line 662

and others

@laudes,

I’m not sure that putting ob_start at the beginning of function.php is a good idea, especially if you aren’t closing it. You are basically throwing everything into server memory when you do that. Besides, if functions.php is echoing something where it shouldn’t be the fix would be to find what is being echoed and stop it, rather than just cover it up.

@ultrageek,

First thing I’d try would be re-uploading all of your files directory by directory. FTP can hang and files end up missing or corrupt.

I have copied the whole WP directory structure to the server at least 6 times. Of course, this time it worked. It seems that I just needed someone to make the official suggestion for it to work for me.
Thanks.

I have copied the whole WP directory structure to the server at least 6 times.

Depending on your FTP software and your finickiness of your server, it might just take that many times. I speak from experience with one particular server. Other servers have done better. I’ve given up on FTPing the wordpress directory and instead upload subdirectories– wp-admin, wp-includes… Even those I’ll do twice to make sure everything went. (My FTP software will tell me before it uploads what has and hasn’t been uploaded previously, so I can skip files already sent.)

Removing the blank lines in my functions.php file (in my current theme’s folder) solved the header issue for me.

@apljdi

I agree with your statement as to server memory etc. I strongly suggest one use this only for development (localhost). On 2 occasions I’ve experienced “Mod header” issues , for it to simply disappear once all back-end coding has been completed.

Samboll – you are amazing! thankyou!

Samboll – I dont have any blank line but this script in lines 663 to 670:

663 // Set httponly if the php version is >= 5.2.0
664 if ( version_compare(phpversion(), ‘5.2.0’, ‘ge’) ) {
665 setcookie($auth_cookie_name, $auth_cookie, $expire, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN, $secure, true);
666 setcookie($auth_cookie_name, $auth_cookie, $expire, ADMIN_COOKIE_PATH, COOKIE_DOMAIN, $secure, true);
667 setcookie(LOGGED_IN_COOKIE, $logged_in_cookie, $expire, COOKIEPATH, COOKIE_DOMAIN, false, true);
668 if ( COOKIEPATH != SITECOOKIEPATH )
669 setcookie(LOGGED_IN_COOKIE, $logged_in_cookie, $expire, SITECOOKIEPATH, COOKIE_DOMAIN, false, true);
670 } else {

see no blank lines.. and have the same problem..

any ideas?

i get the same as Babysenkids.nl

Any idea why this might be happening? it locks me out of the admin panel, There are no spaces on the code… the lines of code it refers to is:

setcookie($auth_cookie_name, $auth_cookie, $expire, PLUGINS_COOKIE_PATH, $cookie_domain, $secure);
setcookie($auth_cookie_name, $auth_cookie, $expire, ADMIN_COOKIE_PATH, $cookie_domain, $secure);
setcookie(LOGGED_IN_COOKIE, $logged_in_cookie, $expire, COOKIEPATH, $cookie_domain);
if ( COOKIEPATH != SITECOOKIEPATH )
setcookie(LOGGED_IN_COOKIE, $logged_in_cookie, $expire, SITECOOKIEPATH, $cookie_domain);
}
}
endif;

This is the second time it has happened now.. I wondering If its to do with plugins? I’ve tried taking the plugins out of the plugins folder but it seems to have little effect..

any ideas on this?

I’ve worked out that it has something to do with the theme I’ve created.. when I take the theme out of the theme folder using ftp, the problem goes away…

the pluggable.php seems to be affected.. has anyone found a solution to this? I’m at a dead at with it at the minute..

Samboll: right on the money!

one of the quicker WP solutions…

Thank You!