Wordpress Error: Warning: Cannot modify header information

wordpress

Yesterday I was helping a reader solving his Wordpress error, so I thought I might as well write an entry, just in case we all encounter this in the future. If you ever run across this error (or warning) in your Wordpress with the message saying:

Warning: Cannot modify header information – headers already sent by (output started at //home/htdocs/wordpress/wp-config.php:1) in /home/htdocs/wordpress/wp-login.php on line 12

or something similar, chances are you have messed up your wp-config.php leaving some unnecessary spaces inside.

Solution

Download your wp-config.php down via FTP (Edit directly if you have SSH access)
Open wp-config with your favourite editor, and remove all spaces before "<?php" and after "?>"
Upload and replace.

You are adviced to make backup of any files you edited.

Comments

Eric Hamby January 22nd, 2008

im getting this

Warning: Cannot modify header information – headers already sent by (output started at /homepages/20/d159566430/htdocs/jericoinfo/wp-includes/widgets.php:2) in /homepages/20/d159566430/htdocs/jericoinfo/wp-content/plugins/BAStats/BAStats_logger.php on line 99

and of course i cant even log in or anything. the later part changed due to the page but the widgets.php seems to be the sourse of all the trouble. i looked through the file and there didnt seem to be any problems that i can see.. any ideas?

please help

http://jericosystems.info
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Eric Hamby January 22nd, 2008

just letting you know i fixed it so you didnt waste your time trying to help. feel free to stop by though.
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Marian Matthis April 5th, 2008

Thanks! I was having the same problem. Somehow, I ended up with spaces after “?>”, but getting rid of them fixed it!
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HeyGabe April 12th, 2008

Rock on! “chances are you have messed up your wp-config.php leaving some unnecessary spaces inside.”

Exactly!
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danielgbr June 21st, 2008

Hey Hongkiat! I host my blog at Bluehost, installed wordpress and installed a theme called Demure Composure. Everytime i do anything i get a Header Error… when I log out via my blog i get this error:
Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-login.php on line 202

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-login.php on line 214

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 570

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 571

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 574

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 575

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 576

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 577

Warning: Cannot modify header information – headers already sent by (output started at /home/ibawebco/public_html/jiba/wp-content/themes/Composure/functions.php:1190) in /home/ibawebco/public_html/jiba/wp-includes/pluggable.php on line 694
What should I do!? I am totally a newb at this… thanx in advance
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hongkiat June 21st, 2008

@danielgbr double check your header.php. See if there’s a blank newline on the top of the page. Sometimes this error creates that following warning.
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karol June 22nd, 2008

it doesn’t work… :/
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Jane Trimmer June 24th, 2008

Thanks a lot for this! It was a great help and solved my problem.

Jane
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_Gian July 14th, 2008

Thank you, you solved my problem.
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blake July 24th, 2008

Hi I have the same problem as you danielgbr….I have tried many things but nothing helped…where was the problem if you were able to fix it??
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Jaime Creixems July 26th, 2008

I can’t believe this, I told many of my clients that I cannot sell them WP in spanish because when I change the wp-config file to put it in spanish the WP messed up.

I can’t believe this, you solved my problem, but is unbelievable that the spaces wer already there but only start messing around if I modify the file.

Thanks a lot for fixing this serious WTF
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RovingCalypso August 22nd, 2008

I’ll be darned. I reinstalled the wordpress twice as I was getting this error when i upgraded.

Who could’ve thought it were the space. Lol
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Anouar August 24th, 2008

Thanks, great post

i had the same problem but i jut apply this solution (delete some space) and it work perfectly.
Reply
purab kharat August 25th, 2008

i solved this problem
use this code
<?
//dont use header function in wordpress-wp_signup.php
global $domain;
global $path;
//change urlnew variable as per requirment
$urlnew = “http://”.$domain.$path.”/wp-admin/admin.php;

echo “”;
echo “location = ‘$urlnew’;”;
echo “”;
echo $urlnew;
?>
Purab Kharat
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Beaulife September 21st, 2008

Other than wp-config.php & header.php, any other possible cause of this error? I tried to delete those spaces but still the same problem. May I have your suggestions?
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Beaulife September 23rd, 2008

I just realized that the Google Analytic had created this trouble for my blog. I used to view my blog in Firefox but no error, but I found error from Google Analytic in IE. After I deactivated the Google Analytic Plugin, then all the problems solved. Just to share with all.
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tkins recipes September 27th, 2008

thanks for letting others know. this helped me out to when i encountered the problem
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jen September 27th, 2008

just wanted to let you know this saved me quite a bit of time tonight… thks for posting!
Reply
Gustavo D. September 30th, 2008

Resolveu meu problema! Obrigado!
Reply
Aleks October 29th, 2008

So simple, and yet effective. It helped me transfering my blog.
Reply
Raj October 31st, 2008

Thank you dudes, it worked..
Reply
Boris December 3rd, 2008

It worked for me! Removed to blank rows at the bottom

Thanks.
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Abs January 17th, 2009

Thanks Bro, worked a treat after i removed the blank spaces.
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Andy January 27th, 2009

Hi,

I had a similar problem and found it was caused by a recent update to one of my plugins, removed the plugin and this fixed the error.

Andy
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Fird February 3rd, 2009

Thanks for the space tip. It’s been driving me nuts for hours!
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cnpabi February 4th, 2009

:)
doesn’t work…
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Alex February 6th, 2009

Thanks, it solved the problem!
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Javier February 7th, 2009

Now I can start my blog. Thanks a lot!!!!!!!!!!!
You are the best
/Javier
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Lindsey February 15th, 2009

Thanks so much, this really helped me and saved a lot of time!
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Bumpas March 13th, 2009

You’re my hero. Thanks. It was so simple. I didn’t even see it.
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Joreel March 13th, 2009

Warning: Cannot modify header information in Wordpress

I encountered the same problem… but I fixed using these following methods..

http://emag.joreeldiaz.com/warning-cannot-modify-header-information-in-wordpress/
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Mike Pantoja March 16th, 2009

Holy Crap! All I had to do was check each file that showed up in the headers and TA DA! Problem solved. Thank you so much for posting this.
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Girish March 16th, 2009

Hi,

When i am adding or deleting post in wordpres admin i am getting below error.

Warning: Cannot modify header information – headers already sent by (output started at /home/content/d/i/c/diclemen18/html/wp/wp-admin/includes/file.php:1539) in /home/content/d/i/c/diclemen18/html/wp/wp-includes/pluggable.php on line 850

Can anyone please help me.

Thanks
Reply
Paul March 22nd, 2009

Ja, genau so hatte ich es auch. Aber nun ist das Problem weg :)
Reply
Michael L. March 26th, 2009

Wow, no friggin wayyyy. I have tried everything……. just as well as you all have im sure. And the freakin spaces were the problem. Im not sure which file, I went through a lot of em and almost cant believe that no more errors. :-) What a relief
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Martijn March 27th, 2009

Tnx! That solved it!
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kristine April 29th, 2009

I messed up my upgrade :( Please help. I tried doing what you said here…but to no avail…I can’t login to wp-admin too :(

Warning: Cannot modify header information – headers already sent by (output started at /homepages/6/d262576222/htdocs/wp-settings.php:630) in /homepages/6/d262576222/htdocs/wp-includes/pluggable.php on line 850
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kristine April 29th, 2009

i did it! :) figured out eventually…i had like 3 or 4 files that needed the editing and that was it :)

thanks again for this info:)
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josh May 5th, 2009

Thanks for posting this, unfortunately the spaces wasn’t the problem but I saw a comment here about google analytics, so I removed the plugin and it works. thanks hongkiat & beaulife!
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claudia June 3rd, 2009

You have saved my hide! Thanks a billion! Now, how tha heck did that happen, I will never know…
Reply
Energy Care July 2nd, 2009

Thanks!! this helped a bunch!! the problem ended up being a plugin i was using…random image generator…not sure what was not working, just deleted it and now im up and running!
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TG July 31st, 2009

Thanks! This was exactly the problem I had, and such a sneaky error to detect!
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Sverre August 10th, 2009

Thanks! that was the missing info I needed
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Marius August 10th, 2009

Hi, I’m having the same problem with BBPress, but theres no extra spaces in that file. Here is the errormessage:

Warning: Cannot modify header information – headers already sent by (output started at /home/michael/public_html/forum/bb-config.php:1) in /home/michael/public_html/forum/bb-includes/backpress/class.wp-auth.php on line 273

Warning: Cannot modify header information – headers already sent by (output started at /home/michael/public_html/forum/bb-config.php:1) in /home/michael/public_html/forum/bb-includes/backpress/class.wp-auth.php on line 273

Warning: Cannot modify header information – headers already sent by (output started at /home/michael/public_html/forum/bb-config.php:1) in /home/michael/public_html/forum/bb-includes/backpress/class.wp-auth.php on line 273

Warning: Cannot modify header information – headers already sent by (output started at /home/michael/public_html/forum/bb-config.php:1) in /home/michael/public_html/forum/bb-includes/backpress/class.wp-auth.php on line 273

Warning: Cannot modify header information – headers already sent by (output started at /home/michael/public_html/forum/bb-config.php:1) in /home/michael/public_html/forum/bb-includes/backpress/class.wp-auth.php on line 273

Warning: Cannot modify header information – headers already sent by (output started at /home/michael/public_html/forum/bb-config.php:1) in /home/michael/public_html/forum/bb-includes/functions.bb-pluggable.php on line 232
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Sergey Rusak August 13th, 2009

Thank you, it was easy. It took me 3 hours to figure out untill I found your post.
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Rob Butz September 4th, 2009

Hi folks. Well after looking at the error info, it looks as if the issue is NOT my wp-config.php or wp-login.php files but my themes functions.php file. I removed spaces at the end of that one.

It makes sense as that could’ve been the only thing I might have modified and my site was “suddenly” not working.

So.. checking your theme files functions.php is also recommended.

Cheers

R o B
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nabtron September 27th, 2009

the error is in the file that is being said in the error first line. this is caused by extra spaces before or after the php code

check out the explaination here:

http://tech.nabtron.com/wordpress-plugin-error-warning-session_start-function-session-start-cannot-send-session-cache-limiter-headers-already-sent-output-started-at/525/
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Richard October 21st, 2009

Got to say thank you, yesterday i locked down my site, and had to make small changes in the wp-config file

any way today i had this error showing,

then

found you on google, made the small change of deleting the space

and bingo my site is now up and running correctly..

http://www.guesthousepattaya.com

Thank you
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Rob November 14th, 2009

Thanks a lot, I had an error after installing a new theme so I went to the file specified and there was a blank line just like you mentioned. Erased the blank line and no more problems.
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Jacob November 17th, 2009

This worked for me! You are awesome!
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