Title: Cannot modify header info error Last modified: August 22, 2016 --- # Cannot modify header info error * Resolved [LovegroveShop](https://wordpress.org/support/users/lovegroveshop/) * (@lovegroveshop) * [11 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/) * I’ve logged in and get this error. * I’m using WP 4.1 WooCommerce Multilingual 3.4.3 WPML Media 2.1.8 WPML Multilingual CMS 3.1.8.4 WPML String Translation 2.0.14 WPML Translation Management 1.9.9WPML Translation Management * Warning: Cannot modify header information – headers already sent by (output started at /home/content/32/8672132/html/newshop/wp-content/plugins/woocommerce-multilingual/ inc/multi-currency.class.php:1055) in /home/content/32/8672132/html/newshop/wp- includes/option.php on line 748 * Warning: Cannot modify header information – headers already sent by (output started at /home/content/32/8672132/html/newshop/wp-content/plugins/woocommerce-multilingual/ inc/multi-currency.class.php:1055) in /home/content/32/8672132/html/newshop/wp- includes/option.php on line 749 * Looked up this type of error and suggests it could be relating to closing php code incorrectly. Can you check? * Many thanks. * [https://wordpress.org/plugins/woocommerce-multilingual/](https://wordpress.org/plugins/woocommerce-multilingual/) Viewing 10 replies - 1 through 10 (of 10 total) * [Bernat Torras (a11n)](https://wordpress.org/support/users/bernattorras/) * (@bernattorras) * [11 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671584) * Hi LovegroveShop, * It can be related to a compatibility conflict. Could you try to disable all your plugins except WooCommerce and WPML plugins and check if the Warnings still persist? If not, try to enable your plugins again, one by one, and check which is the one that brings the warnings up. We’ll work to make it compatible. 🙂 * Thanks, Bernat * Thread Starter [LovegroveShop](https://wordpress.org/support/users/lovegroveshop/) * (@lovegroveshop) * [11 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671664) * Thanks for the quick reply. I’ve deactivated all other plugins and get the same error. 🙁 * I’ve also tried switching from Twenty Fifteen theme to Twenty Fourteen theme. Both themes are out-the-box uncustomised. * Deactivating any WPML plugins removes the error but then your plugin won’t work. 🙁 * Many thanks for your help. * [Bernat Torras (a11n)](https://wordpress.org/support/users/bernattorras/) * (@bernattorras) * [11 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671743) * Hi LovegroveShop, * In this case I think the best will be to check your site configuration directly. Could you please open a new ticket in our wpml.org support forum? This way we’ll be able to ask you for private data and check your site to help you in a better way. 🙂 * Thanks, Bernat * Thread Starter [LovegroveShop](https://wordpress.org/support/users/lovegroveshop/) * (@lovegroveshop) * [11 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671749) * It appears the error message has now disappeared. : / * I can’t say for certain what I did. I carried on regardless whilst waiting for a response. I’ve re-activated all the plugins added new plugins and configured a few more WPML settings. * Can I now be certain the error isn’t there anymore if it’s not displaying in the admin area? * Many thanks for your help. Much appreciated. 🙂 * [Bernat Torras (a11n)](https://wordpress.org/support/users/bernattorras/) * (@bernattorras) * [11 years, 2 months ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671759) * Hi LovegroveShop, * Well, I can’t guarantee you as I’m still not sure what was the issue… It can be related to some plugin activation or mis-configuration… So in that case, yes, a new activation can fix the issue definitely But anyway, I’d suggest you to keep an eye on this to be sure that it doesn’t happen again. If it gets back, please let us know. * Thanks, Bernat * [yococcinelle](https://wordpress.org/support/users/yococcinelle/) * (@yococcinelle) * [11 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671781) * Hi Bernattorras, * I’ve the same error when i’m log in to wp-admin (just see this error once a day). * Warning: Cannot modify header information – headers already sent by (output started at /wp-content/plugins/woocommerce-multilingual/inc/multi-currency.class.php: 902) in wp-includes/option.php on line 749 * I deactivated each plugin except wpml but the error doesn’t disappear… I take a look in the code in option.php it’s a setcookie function at this line and in multi-currency.class.php it’s the multi-currency drop down menu (who doesn’t work by the way). * WP V4.1.1 woocommerce ML v3.5.1 WPML ML CMS v3.1.8.4 WPML String Translation v2.0.14 WPML Translation Management v1.9.9 WPML Media v2.1.8 * Thanks, * Yohann * [yococcinelle](https://wordpress.org/support/users/yococcinelle/) * (@yococcinelle) * [11 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671782) * I check in the error_log and i’ve got many errors connected to multi-currency like this one : * [21-Feb-2015 00:24:11 UTC] Erreur de la base de données WordPress You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ‘) AND meta_key=’_wcml_custom_prices_status” at line 1 pour la requête SELECT post_id, meta_value FROM wp_postmeta WHERE post_id IN() AND meta_key=’_wcml_custom_prices_status’ faite par require(‘wp-blog-header. php’), require_once(‘wp-includes/template-loader.php’), include(‘/themes/liselondonv2/ taxonomy-product_cat.php’), wc_get_template, include(‘/themes/liselondonv2/woocommerce/ archive-product.php’), wc_get_template_part, load_template, require(‘/themes/ liselondonv2/woocommerce/content-product.php’), post_class, get_post_class, apply_filters(‘ post_class’), call_user_func_array, wc_product_post_class, WC_Product->is_on_sale, WC_Product->get_sale_price, WC_Product->__get, get_post_meta, get_metadata, apply_filters(‘ get_post_metadata’), call_user_func_array, WCML_Multi_Currency_Support->product_price_filter, WCML_Multi_Currency_Support->get_product_custom_prices * Is it connected? * Yohann * [robert.v](https://wordpress.org/support/users/robertv-1/) * (@robertv-1) * [11 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671783) * I seems that some of the errors are coming from your theme, does this issue persist on a default theme like twenty-fourteen? * If the issue persists with the default theme and all non WPML plugins deactivated I suggest that you open a ticket on WPML.org so that we may take a close look at the issue. * [yococcinelle](https://wordpress.org/support/users/yococcinelle/) * (@yococcinelle) * [11 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671784) * Hi Robert, * Changing the theme doesn’t resolve my problem. I open a ticket on WPML * Thank’s * [StanLight](https://wordpress.org/support/users/stanlight/) * (@stanlight) * [11 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671785) * To those who are saying this could be related to a plugin … that doesn’t look like the case. * I’ve got a brand new installation of WP – no plugins, just one page created – and I get these errors: * Warning: Cannot modify header information – headers already sent by (output started at [path on my server](http://codex.wordpress.org/path_on_my_server) /wp-admin/ includes/plugin-install.php:83) in [path on my server](http://codex.wordpress.org/path_on_my_server)/ wp-includes/option.php on line 748 * and * Warning: Cannot modify header information – headers already sent by (output started at [path on my server](http://codex.wordpress.org/path_on_my_server) /wp-admin/ includes/plugin-install.php:83) in [path on my server](http://codex.wordpress.org/path_on_my_server)/ wp-includes/option.php on line 749 * I did enable one of the “bundled themes” but I believe I was getting that error even before enabling that theme (which theme I can’t seem to now get rid of but that’s a different thread!) * No matter what theme I choose I’m getting the above error messages whenever I click on Plugins>Add new in the control panel. Viewing 10 replies - 1 through 10 (of 10 total) The topic ‘Cannot modify header info error’ is closed to new replies. * ![](https://ps.w.org/woocommerce-multilingual/assets/icon-256x256.png?rev=2937122) * [WPML Multilingual & Multicurrency for WooCommerce](https://wordpress.org/plugins/woocommerce-multilingual/) * [Frequently Asked Questions](https://wordpress.org/plugins/woocommerce-multilingual/#faq) * [Support Threads](https://wordpress.org/support/plugin/woocommerce-multilingual/) * [Active Topics](https://wordpress.org/support/plugin/woocommerce-multilingual/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/woocommerce-multilingual/unresolved/) * [Reviews](https://wordpress.org/support/plugin/woocommerce-multilingual/reviews/) ## Tags * [header](https://wordpress.org/support/topic-tag/header/) * [Modify](https://wordpress.org/support/topic-tag/modify/) * [php](https://wordpress.org/support/topic-tag/php/) * [warning](https://wordpress.org/support/topic-tag/warning/) * 10 replies * 5 participants * Last reply from: [StanLight](https://wordpress.org/support/users/stanlight/) * Last activity: [11 years, 1 month ago](https://wordpress.org/support/topic/cannot-modify-header-info-error/#post-5671785) * Status: resolved