Title: Cannot modify header information Last modified: August 19, 2016 --- # Cannot modify header information * [Rudolfs](https://wordpress.org/support/users/rudolfs/) * (@rudolfs) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/) * during the installation on my netcup webspace i got the error that something cant be modified. i do not have the message anymore. but it seems that the installation finished successfully. then i came to the login site and the site loaded very long. then a error came: * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-login.php on line 255 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-login.php on line 267 * what i have to do? Viewing 12 replies - 1 through 12 (of 12 total) * Thread Starter [Rudolfs](https://wordpress.org/support/users/rudolfs/) * (@rudolfs) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049822) * and after loggin ivh got * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-login.php on line 255 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-login.php on line 267 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-includes/ pluggable.php on line 649 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-includes/ pluggable.php on line 650 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-includes/ pluggable.php on line 651 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web145/html/wp-config.php:1) in /var/www/web145/html/wp-includes/ pluggable.php on line 850 * [Len](https://wordpress.org/support/users/lenk/) * (@lenk) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049824) * Check for whitespace before and after the opening and closing `` tags in `wp-config.php` * [ziphera](https://wordpress.org/support/users/ziphera/) * (@ziphera) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049837) * All five of my wordpress blogs are giving me similar warning messages as Rudolfs. They were working fine yesterday. My blogs have been up and running just fine for months so it is not an installation problem. I have just checked the wp-config. php file and there are no spaces. What could be the problem? * [Len](https://wordpress.org/support/users/lenk/) * (@lenk) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049839) * Are you sure it’s the same error message and not a variation? When interpreting these error messages the file mentioned first is the culprit while the second is the victim. * In the case of Rudolf –> wp-config.php:1 (that’s line 1) –> excessive whitespace * [ziphera](https://wordpress.org/support/users/ziphera/) * (@ziphera) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049842) * On the login page I receive the following warnings: * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-login.php on line 255 * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-login.php on line 267 * When I try to log in I get the warning messages as follows: * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-login.php on line 255 * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-login.php on line 267 * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-includes/pluggable. php on line 649 * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-includes/pluggable. php on line 650 * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-includes/pluggable. php on line 651 * Warning: Cannot modify header information – headers already sent by (output started at /home/pillslim/public_html/diet-pills-online-blog/wp-includes/default-filters. php:204) in /home/pillslim/public_html/diet-pills-online-blog/wp-includes/pluggable. php on line 850 * Again, my blogs were working fine yesterday and now I get these errors. * [Len](https://wordpress.org/support/users/lenk/) * (@lenk) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049845) * I had a quick look at your site. * The file `/wp-includes/default-filters.php` should only have 202 lines. What’s on line 204 of your copy? * [ziphera](https://wordpress.org/support/users/ziphera/) * (@ziphera) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049897) * It looks like the code has been hacked. On line 204 the code is: * * I deleted the code and the blog is working fine now. Is there a security step that I should be doing so that this doesn’t happen again? * [Len](https://wordpress.org/support/users/lenk/) * (@lenk) * [17 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1049899) * [@ziphera](https://wordpress.org/support/users/ziphera/) * There’s a ton of info in the threads below. * [http://wordpress.org/search/hacked?forums=1](http://wordpress.org/search/hacked?forums=1) * [ESP](https://wordpress.org/support/users/esp/) * (@esp) * [17 years ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1050106) * Hi LenK, * I run into a similar issue on my installation! The two warnings before log in are the same, the massages after log in are: * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web2063/html/wordpress/wp-config.php:1) in /var/www/web2063/html/ wordpress/wp-login.php on line 255 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web2063/html/wordpress/wp-config.php:1) in /var/www/web2063/html/ wordpress/wp-login.php on line 267 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web2063/html/wordpress/wp-config.php:1) in /var/www/web2063/html/ wordpress/wp-includes/pluggable.php on line 649 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web2063/html/wordpress/wp-config.php:1) in /var/www/web2063/html/ wordpress/wp-includes/pluggable.php on line 650 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web2063/html/wordpress/wp-config.php:1) in /var/www/web2063/html/ wordpress/wp-includes/pluggable.php on line 651 * Warning: Cannot modify header information – headers already sent by (output started at /var/www/web2063/html/wordpress/wp-config.php:1) in /var/www/web2063/html/ wordpress/wp-includes/pluggable.php on line 850 * Really appreciate your help!! Thanks! * [ESP](https://wordpress.org/support/users/esp/) * (@esp) * [17 years ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1050107) * Additional information: * I checked the beginning and the end of the file for whitespace, but found everything clean… * [ESP](https://wordpress.org/support/users/esp/) * (@esp) * [17 years ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1050108) * Hi All, * Issue is solved by: * 1.) extracting WordPress installation zip again. 2.) Open the file in Notepad( not in UEdit like last time) 3.) Changing settings. 4.) Uploading to webspace. 5.) Working fine! * It looks like that editing the file in UEdit was the issue! * May this helps, ESP. * [barts](https://wordpress.org/support/users/barts/) * (@barts) * [16 years, 4 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1050175) * Old thread, new experience. I searched the entire web for a solution to this ( no, really … ;-)) Finally, doing what ESP suggests above worked. I extracted a fresh copy of wp-config-sample.php from the downloaded WordPress source, edited it to my needs (using Notepad) and saved it. Done! * One more remark: I’m using WordPress 2.9.1 and the wp-config.php file does NOT have a closing `?>`. Viewing 12 replies - 1 through 12 (of 12 total) The topic ‘Cannot modify header information’ is closed to new replies. * In: [Installing WordPress](https://wordpress.org/support/forum/installation/) * 12 replies * 5 participants * Last reply from: [barts](https://wordpress.org/support/users/barts/) * Last activity: [16 years, 4 months ago](https://wordpress.org/support/topic/cannot-modify-header-information-24/#post-1050175) * Status: not resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics