Title: Error Message Last modified: August 20, 2016 --- # Error Message * [dmalvarez](https://wordpress.org/support/users/dmalvarez/) * (@dmalvarez) * [14 years ago](https://wordpress.org/support/topic/error-message-123/) * I receive the following messages when I try to log into the back-end of my website: * Warning: Missing argument 2 for woocommerce_load_persistent_cart() in /home/electpas/ public_html/wp-content/plugins/woocommerce/woocommerce-core-functions.php on line 175 * Warning: Cannot modify header information – headers already sent by (output started at /home/electpas/public_html/wp-content/plugins/woocommerce/woocommerce-core- functions.php:175) in /home/electpas/public_html/wp-includes/pluggable.php on line 934 * I receive the following message when I try to view my website: * Fatal error: Call to undefined method WP_Query::is_main_query() in /home/electpas/ public_html/wp-content/plugins/woocommerce/classes/class-wc-query.php on line 34 * HELP! HOW CAN I FIX THIS! Viewing 8 replies - 1 through 8 (of 8 total) * [Mark Ratledge](https://wordpress.org/support/users/songdogtech/) * (@songdogtech) * [14 years ago](https://wordpress.org/support/topic/error-message-123/#post-2777552) * Try the usual fixes: Upgrade/reupload Woocommerce, update Woo Themes framework update the Woo Theme itself. * Thread Starter [dmalvarez](https://wordpress.org/support/users/dmalvarez/) * (@dmalvarez) * [14 years ago](https://wordpress.org/support/topic/error-message-123/#post-2777555) * It won’t even allow me to log in the back end to make changes. When I type my log in and password I only see a white screen with that black text. * [Mark Ratledge](https://wordpress.org/support/users/songdogtech/) * (@songdogtech) * [14 years ago](https://wordpress.org/support/topic/error-message-123/#post-2777567) * Use FTP to replace the folders. See [Filezilla](http://filezilla-project.org/) and [FTP Clients « WordPress Codex](http://codex.wordpress.org/FTP_Clients). * [ianarmstrong](https://wordpress.org/support/users/ianarmstrong/) * (@ianarmstrong) * [14 years ago](https://wordpress.org/support/topic/error-message-123/#post-2777744) * I have only ever seen this error after moving WordPress from a DEV to a permanent location. It occurs because of an issue with the Janrain Engage plugin, post move. * Check your plugins, one of them is causing the issue. * [eldiekenjewel](https://wordpress.org/support/users/eldiekenjewel/) * (@eldiekenjewel) * [13 years, 9 months ago](https://wordpress.org/support/topic/error-message-123/#post-2777820) * Hi, * I’m have the same trouble installig woocommerce, my website now only shows: Fatal error: Call to undefined method WP_Query::is_main_query() in /homepages/ 44/d383697281/htdocs/app383697293/wp-content/plugins/woocommerce/classes/class- wc-query.php on line 54 * I’ve already tried all the other plugins and reuploaded the woocommerce plugin. Anyone any idea what might be the cause and how I could solve it? * Thank you * [eldiekenjewel](https://wordpress.org/support/users/eldiekenjewel/) * (@eldiekenjewel) * [13 years, 9 months ago](https://wordpress.org/support/topic/error-message-123/#post-2777821) * Btw when I click on the Woocommerce configuracion button in the WPmenu, I get this message: * Fatal error: Call to undefined method stdClass::add_help_tab() in /homepages/ 44/d383697281/htdocs/app383697293/wp-content/plugins/woocommerce/admin/woocommerce- admin-content.php on line 23 * [dextrous](https://wordpress.org/support/users/dextrous/) * (@dextrous) * [13 years, 3 months ago](https://wordpress.org/support/topic/error-message-123/#post-2777842) * Does anyone have a solution for this error? I am trying to install WooCommerce without any luck. * I have created a fresh install of WordPress locally on my dev machine, have deactivated all plugins except WooCommerce so there should be no conflicts, have re-installed the plugin numerous times, have made sure everything is up to date, and am using the WooTheme MyStile. I can get into sections of the Admin site but whenever I try to view the front end I get: * Fatal error: Call to undefined method WP_Query::is_main_query() in C:\…\wp-content\ plugins\woocommerce\classes\class-wc-query.php on line 54 * System Status is as follows: WooCommerce version 1.6.6 WordPress version WP 3.2.1 Installed plugins WooCommerce by WooThemes version 1.6.6 Settings * Server Environment PHP Version 5.2.9-2 Server Software Apache/2.2.11 (Win32) PHP/5.2.9-2 WP Max Upload Size 2MB Server upload_max_filesize 2MB Server post_max_size 8MB WP Memory Limit 64MB WP Debug Mode No WC Logging Log directory is writable. * Thanks, I would really appreciate the help. * [dextrous](https://wordpress.org/support/users/dextrous/) * (@dextrous) * [13 years, 3 months ago](https://wordpress.org/support/topic/error-message-123/#post-2777843) * False Alarm! * My dev version of WordPress was showing as up to date even though it is was version 3.2.1. (Strange!) * I’ve upgraded to 3.5.1 and all is working perfectly. Viewing 8 replies - 1 through 8 (of 8 total) The topic ‘Error Message’ is closed to new replies. ## Tags * [error message](https://wordpress.org/support/topic-tag/error-message/) * [fatal error](https://wordpress.org/support/topic-tag/fatal-error/) * [plug-ins](https://wordpress.org/support/topic-tag/plug-ins/) * [warning](https://wordpress.org/support/topic-tag/warning/) * [website down](https://wordpress.org/support/topic-tag/website-down/) * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/) * 8 replies * 5 participants * Last reply from: [dextrous](https://wordpress.org/support/users/dextrous/) * Last activity: [13 years, 3 months ago](https://wordpress.org/support/topic/error-message-123/#post-2777843) * Status: not resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics