Support » Plugin: Google Content Experiments » Error When Viewing Pages with Experiment Code

  • optimized-marketing


    I have multiples sites that I use this plug-in with. It doesn’t seem to be happening on all pages. My sites are set up to not use www. at the beginning. If you put it actually goes to with no issues.

    But when I have a page with the Google Content Experiment option checked and I try to go to it doesnt redirect to as it should it throws the following error.

    “Warning: Cannot modify header information – headers already sent by (output started at /home/bob/public_html/ in /home/bob/public_html/ on line 881”

    Let me know if you need more information

Viewing 2 replies - 1 through 2 (of 2 total)
  • Plugin Author glennm


    On wp-includes/pluggable.php (line 881) the wp_redirect is performed:
    header("Location: $location", true, $status);

    Apparently there already is some output before wp_redirect is executed. I don’t know if this is the most beautiful option and if it will work, but let’s try this:
    In google-content-experiments.php:

    • Place ob_start(); between */ and if ( !defined('WPE_GCE_PATH') )
    • Place ob_end_flush(); right before the closing ?>


    I added your suggested code but that just gave the same error.

    I got it working another way by still using the ob_start(); but I had to added it to the function.php file.

    The code I added to Function.php

    //allow redirection, even if my theme starts to send output to the browser
    add_action(‘init’, ‘do_output_buffer’);
    function do_output_buffer() {

    After I verified this would work. I decided to go back and test your suggestion again. I added ob_start() and ob_end_flush(). Same error so I figured I would just try ob_start() at the begining of google-content-experiments.php and not add ob_end_flush();

    Adding only ob_start() to google-content-experiments.php actually fixed the problem. I am not sure what ob_start(); does or if not including ob_end_flush(); would have any negative impact.

    Let me know if you think this is a valid approach or not.

Viewing 2 replies - 1 through 2 (of 2 total)
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