Title: Error 500 everytime Last modified: March 23, 2021 --- # Error 500 everytime * [giovanni256](https://wordpress.org/support/users/giovanni256/) * (@giovanni256) * [5 years, 2 months ago](https://wordpress.org/support/topic/error-500-everytime/) * Hi there. I just installed WordPress on my Ubuntu 20.04 VPS with 4GB RAM. * Everytime that I change something, activate a plugin or just update permalinks, the website goes in error 500. * What I have to do to fix this issue, is upload the WordPress core files again and then the website comes alive. * How can I avoid this? I already increased the PHP limit to 3000M. Viewing 4 replies - 1 through 4 (of 4 total) * [George Appiah](https://wordpress.org/support/users/gappiah/) * (@gappiah) * [5 years, 2 months ago](https://wordpress.org/support/topic/error-500-everytime/#post-14224911) * Any number of things can cause this. * Please check your web server logs to see exactly what is triggering this 500 internal server error, and then we can help you fix it. * Thread Starter [giovanni256](https://wordpress.org/support/users/giovanni256/) * (@giovanni256) * [5 years, 2 months ago](https://wordpress.org/support/topic/error-500-everytime/#post-14227414) * I tried to install the same backup also in localhost, using XAMPP. Just visiting the website 2-3 times I get this error: * `Fatal error: Uncaught Error: Call to undefined function wp() in G:\xampp\apps\ wordpress\htdocs\wp-blog-header.php:16 Stack trace: #0 G:\xampp\apps\wordpress\ htdocs\index.php(17): require() #1 {main} thrown in G:\xampp\apps\wordpress\htdocs\ wp-blog-header.php on line 16` * Also this error: `Fatal error: Uncaught Error: Call to undefined function nocache_headers() in G:\xampp\apps\wordpress\htdocs\wp-admin\admin.php:36 Stack trace: #0 G:\xampp\ apps\wordpress\htdocs\wp-admin\plugins.php(10): require_once() #1 {main} thrown in G:\xampp\apps\wordpress\htdocs\wp-admin\admin.php on line 36` - This reply was modified 5 years, 2 months ago by [giovanni256](https://wordpress.org/support/users/giovanni256/). * Thread Starter [giovanni256](https://wordpress.org/support/users/giovanni256/) * (@giovanni256) * [5 years, 1 month ago](https://wordpress.org/support/topic/error-500-everytime/#post-14388577) * Up. * Another stack trace, I still can’t solve this issue… * ``` thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:54:46 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:54:48 [error] 108458#108458: *444 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:55:01 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:55:03 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:55:08 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function wp() in />Stack trace: #0 /var/www/mydomain.com/index.php(17): require() #1 {main} thrown in /var/www/mydomain.com/wp-blog-header.php on line 16" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com, r>2021/05/02 00:55:12 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function wp() in />Stack trace: #0 /var/www/mydomain.com/index.php(17): require() #1 {main} thrown in /var/www/mydomain.com/wp-blog-header.php on line 16" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com, r>2021/05/02 00:55:16 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:56:23 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:56:27 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function nocache_h>Stack trace: #0 /var/www/mydomain.com/wp-admin/post.php(12): require_once() #1 {main} thrown in /var/www/mydomain.com/wp-admin/admin.php on line 36" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com, r>2021/05/02 00:56:27 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function send_orig>Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com> Stack trace: #0 {main} thrown in /var/www/mydomain.com/wp-admin/admin-ajax.php on line 25" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com>2021/05/02 00:56:32 [error] 108458#108458: *441 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function wp() in />Stack trace: #0 /var/www/mydomain.com/index.php(17): require() #1 {main} thrown in /var/www/mydomain.com/wp-blog-header.php on line 16" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com, r>2021/05/02 00:58:50 [error] 108458#108458: *471 FastCGI sent in stderr: "PHP message: PHP Fatal error: Uncaught Error: Call to undefined function wp() in />Stack trace: #0 /var/www/mydomain.com/index.php(17): require() #1 {main} thrown in /var/www/mydomain.com/wp-blog-header.php on line 16" while reading response header from upstream, client: 5.77.68.225, server: mydomain.com, r> ``` - This reply was modified 5 years, 1 month ago by [giovanni256](https://wordpress.org/support/users/giovanni256/). - This reply was modified 5 years, 1 month ago by [giovanni256](https://wordpress.org/support/users/giovanni256/). * Thread Starter [giovanni256](https://wordpress.org/support/users/giovanni256/) * (@giovanni256) * [5 years, 1 month ago](https://wordpress.org/support/topic/error-500-everytime/#post-14390279) * I analyzed the errors and I found that these calls are causing the error: * ``` send_origin_headers(); nocache_headers(); wp(); ``` * What can I do? Viewing 4 replies - 1 through 4 (of 4 total) The topic ‘Error 500 everytime’ is closed to new replies. * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/) * 4 replies * 2 participants * Last reply from: [giovanni256](https://wordpress.org/support/users/giovanni256/) * Last activity: [5 years, 1 month ago](https://wordpress.org/support/topic/error-500-everytime/#post-14390279) * Status: not resolved ## Topics ### Topics with no replies ### Non-support topics ### Resolved topics ### Unresolved topics ### All topics