Cannot modify header information – headers already sent

  • Resolved Steve Parry

    (@vidarparry)


    7 years, 4 months ago

    Hi everyone,
    Not sure when this started or why (I haven’t changed my site for quite some time), but mobile (Android 7.1.2 Chrome and Firefox) access to my web site gives the white screen of death displaying just “error”. Works OK on an Apple.

    I accept this may be an Android, Nexus 5X or even a problem with my phone, but the error seems a bit mysterious so I’m hoping this post will either identify the problem or (when I find the cause) enable someone else to learn from the cause!

    I updated WordPress to 4.8 and all the plugins and the Udesign theme, but it still does the same thing.

    Debug output (on 4.8) is listed below. And the code referred to is the setcookie lines in the following:
    ++++++++++++++++++++++++++++
    /** This filter is documented in wp-includes/pluggable.php */
    if ( ! apply_filters( ‘send_auth_cookies’, true ) ) {
    return;
    }

    // Auth cookies
    setcookie( AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, ADMIN_COOKIE_PATH, COOKIE_DOMAIN );
    setcookie( SECURE_AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, ADMIN_COOKIE_PATH, COOKIE_DOMAIN );
    setcookie( AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
    setcookie( SECURE_AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, PLUGINS_COOKIE_PATH, COOKIE_DOMAIN );
    setcookie( LOGGED_IN_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
    setcookie( LOGGED_IN_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

    // Settings cookies
    setcookie( ‘wp-settings-‘ . get_current_user_id(), ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH );
    setcookie( ‘wp-settings-time-‘ . get_current_user_id(), ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH );

    // Old cookies
    setcookie( AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
    setcookie( AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
    setcookie( SECURE_AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
    setcookie( SECURE_AUTH_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );

    // Even older cookies
    setcookie( USER_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
    setcookie( PASS_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, COOKIEPATH, COOKIE_DOMAIN );
    setcookie( USER_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
    setcookie( PASS_COOKIE, ‘ ‘, time() – YEAR_IN_SECONDS, SITECOOKIEPATH, COOKIE_DOMAIN );
    }
    endif;
    +++++++++++++++++++++++

    Loading the site on PC web browser works fine. I looked at pluggable.php and found two extra blank lines after the last endif; statement – removed them but it still fails.

    Any other suggestions?

    Thanks in advance.
    Steve

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 942

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 943

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 944

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 945

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 946

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 947

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 950

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 951

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 954

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 955

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 956

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 957

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 960

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 961

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 962

    Warning: Cannot modify header information – headers already sent by (output started at /home/theva/public_html/wp-config.php:97) in /home/theva/public_html/wp-includes/pluggable.php on line 963
    error

Viewing 5 replies - 1 through 5 (of 5 total)
  • Moderator James Huff

    (@macmanx)

    You have unexpected whitespace (either a space or an entire line) on line 97 of the wp-config.php file. See this guide for more info.

    Alternatively, reconstructing the file with a copy of wp-config-sample.php from a fresh download may resolve the issue.

    Thread Starter Steve Parry

    (@vidarparry)

    Thanks James.
    Line 97 of wp-config.php is the define(‘WP_DEBUG’,true); line.

    I’ve reconstructed the file using wp-config-sample.php as a base and the same issue occurs.

    Appreciate any further suggestions….:-)

    Cheers
    …Steve

    Thread Starter Steve Parry

    (@vidarparry)

    whoa <headspin!>.

    I’m running on the original wp-config.php and found that if I access the site on my phone via the mobile network, the site works (which is why it worked on my wife’s iPhone – her wifi was turned off). If I access the site on my phone (or my wifes phone) through my home wifi it fails.

    My PC by default uses a VPN through my home ADSL2, and it works through that. If I turn off the VPN (ie use my standard ADSL2 ISP connection) it fails.

    Can’t get my head around that one. Hope someone can have a brainwave idea! Going to bed now:-(

    Cheers
    …Steve

    Moderator James Huff

    (@macmanx)

    Hm, I wonder if maybe a plugin is involved then, that’s very odd.

    Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.

    If that does not resolve the issue, try switching to the Twenty Seventeen theme to rule-out a theme-specific issue (theme functions can interfere like plugins).

    Thread Starter Steve Parry

    (@vidarparry)

    Rebooted the router – now works.
    Another few hours of my life donated to the mysteries of IT:-)
    Thanks for your help James.
    Cheers
    …Steve

Viewing 5 replies - 1 through 5 (of 5 total)
  • The topic ‘Cannot modify header information – headers already sent’ is closed to new replies.