Cannot Modify Header Information - While trying logging in

Question

I am having the same issue as cited on: https://wordpress.stackexchange.com/questions/80276/cannot-modify-header-information-headers-already-sent-theme-specific-functi

Can you give me a help on that.

I am using Optimize Press Theme

This is the error:

Warning: Cannot modify header information - headers already sent by (output started at /home/talent31/public_html/domain.com/wp-includes/general-template.php:2102) in /home/talent31/public_html/domain.com/wp-includes/option.php on line 568

Warning: Cannot modify header information - headers already sent by (output started at /home/talent31/public_html/domain.com/wp-includes/general-template.php:2102) in /home/talent31/public_html/domain.com/wp-includes/option.php on line 569

Answer 1

wp-includes/general-template.php:2102 is the function wp_admin_css().
On the login page this function is called in login_header().
Your theme or some plugin trys to send an HTTP header after that, probably during the actions login_enqueue_scripts or login_head.

wp-includes/option.php on:569 is in function wp_user_settings(); a cookie is set here. Cookies are HTTP headers, so that cannot work when there was already some output.

Search for something like …

add_action( 'login_head', 'some_function_name' );

… and the registered callback function is probably calling wp_user_settings().