Title: WordPress upgrade – fatal error Last modified: August 20, 2016 --- # WordPress upgrade – fatal error * Resolved [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/) * I updated my wordpress website and then received the below error. Fatal error: Call to undefined function wp() in /home2/rmiller/public_html/wp-blog-header. php on line 14 * I cannot login to WordPress to see the dashboard. * How do I resolve this? Viewing 15 replies - 1 through 15 (of 15 total) * [esmi](https://wordpress.org/support/users/esmi/) * (@esmi) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557748) * Try: – switching to the default theme by renaming your current theme’s folder inside wp-content/themes and adding “-old” to the end of the folder name using [FTP](http://codex.wordpress.org/FTP_Clients) or whatever file management application your host provides. * – [resetting the plugins folder](http://codex.wordpress.org/FAQ_Troubleshooting#How_to_deactivate_all_plugins_when_not_able_to_access_the_administrative_menus.3F) by FTP or phpMyAdmin. * – re-uploading all files & folders – **except** the wp-content folder – from a **fresh** download of WordPress. Make sure that you delete the old copies of files & folder before uploading the new ones. * – running the upgrade manually via wp-admin/upgrade.php * [Rajesh Soni](https://wordpress.org/support/users/rajeshsoni/) * (@rajeshsoni) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557778) * These links might be helpful: * [http://wordpress.org/support/topic/fatal-error-call-to-undefined-function-wp-in-wp-blog-headerphp-on-line-18](http://wordpress.org/support/topic/fatal-error-call-to-undefined-function-wp-in-wp-blog-headerphp-on-line-18) * [http://wordpress.org/support/topic/fatal-error-call-to-undefined-function-wp-in-wp-blog-headerphp-on-line-18-19?replies=7](http://wordpress.org/support/topic/fatal-error-call-to-undefined-function-wp-in-wp-blog-headerphp-on-line-18-19?replies=7) * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557959) * thanks guys. if i follow esmi’s advice will i loose all the customisations that i have done in my theme? * [esmi](https://wordpress.org/support/users/esmi/) * (@esmi) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557960) * No. Your customisations should be safe. * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557962) * ok, I am trying to reset your plugins folder via FTP or the file manager provided in your host’s control panel. I can do steps one and two, but I cannot do step 3 as my site still shows the fatal error. is step 3 via the wordpress dashboard? if it is I cannot access the dashboard * 1. Via FTP or your host’s file manager, navigate to the wp-contents folder (directory) 2. Via FTP or your host’s file manager, rename the folder “plugins” to “plugins. hold” 3. Login to your WordPress administration menus (/wp-admin) 4. Via FTP or your host’s file manager, rename “plugins.hold” back to “plugins” * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557963) * ok i’ve just tried to deactivate plugins by using phpMyAdmin and in the table wp_options, under the option_name column (field) I do not have an active_plugins row * [esmi](https://wordpress.org/support/users/esmi/) * (@esmi) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557964) * And the core files re-upload? * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557966) * no i’ve not been able to deactivate the plugins * [esmi](https://wordpress.org/support/users/esmi/) * (@esmi) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557967) * Why? * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557968) * I first tried to reset the plugins. * I can do steps one and two below, but I cannot do step 3 as my site still shows the fatal error. is step 3 via the wordpress dashboard? if it is I cannot access the dashboard. * 1. Via FTP or your host’s file manager, navigate to the wp-contents folder (directory) 2. Via FTP or your host’s file manager, rename the folder “plugins” to “plugins. hold” 3. Login to your WordPress administration menus (/wp-admin) 4. Via FTP or your host’s file manager, rename “plugins.hold” back to “plugins” * I also tried by using phpMyAdmin and in the table wp_options, under the option_name column (field) I DO NOT have an active_plugins row * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557969) * I’ve deleted the plugin folder and add a fresh folder after re-downloading wordpress. still get the same error. * As my error mentions wp-blog-header.php is it something to do with that file? * [wprock](https://wordpress.org/support/users/wprock/) * (@wprock) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557970) * Download the WP 3.5.1 from wordpress.org Next extract the zip and upload the all files and folders except the wp-content folder via FTP. * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557982) * ok, I think I have really messed my site up know changing a deleting files. In cpanel my disk space usage is over the limit. How do I reset everything on my site so that I’m back to the base of just having wordpress installed and I’ll start again. * Thread Starter [Rachel TED](https://wordpress.org/support/users/rachel-ted/) * (@rachel-ted) * [13 years, 2 months ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3557983) * ok, I think I have really messed my site up know changing a deleting files. In cpanel my disk space usage is over the limit. * How do I reset everything on my site so that I’m back to the base of just having wordpress installed and I’ll start again please? * [BruceWinterton](https://wordpress.org/support/users/brucewinterton/) * (@brucewinterton) * [13 years ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3558076) * I have the same error but I can’t even get into my site. How do I get into my site to make some fixes? Viewing 15 replies - 1 through 15 (of 15 total) The topic ‘WordPress upgrade – fatal error’ is closed to new replies. ## Tags * [fatal](https://wordpress.org/support/topic-tag/fatal/) * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/) * 15 replies * 5 participants * Last reply from: [BruceWinterton](https://wordpress.org/support/users/brucewinterton/) * Last activity: [13 years ago](https://wordpress.org/support/topic/wordpress-upgrade-fatal-error/#post-3558076) * Status: resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics