Title: Error while reading response header from upstream
Last modified: March 21, 2020

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# Error while reading response header from upstream

 *  Resolved [agenciesFirst](https://wordpress.org/support/users/agenciesfirst/)
 * (@agenciesfirst)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/)
 * Hi, I get WordPress critical fallback error in backend when I click on plugin
   settings under NGINX. Under Apache not! I use parallel “EasyUpdateManager”, when
   EUM is deactivated than I get plugin settings and options for WP-Optimize, when
   EasyUpdateManager is parallel active than not. In error log is following entry:
 * >>
    WP_Optim” while reading response header from upstream, client: 84.178.xx.
   xxx, server: xxxxx, request: “GET /wp-admin/admin.php?page=WP-Optimize HTTP/1.1”,
   upstream: “fastcgi://unix:/var/lib/php5-fpm/web74.sock:”, host: … <<
 * So, it’s looks like that exist an php misscoding in plugin sources, the reason
   is not the fast-cgi buffer size in NGINX. Maybe fit the php error in EasyUpdateManager.
 * WordPress 5.3.2, PHP 7.2.8 FPM, NGINX 1.15.2
    EasyUpdateManager free version 
   latest, WP-Optimize free version latest
 * Thanks attention and research

Viewing 5 replies - 1 through 5 (of 5 total)

 *  Plugin Support [bcrodua](https://wordpress.org/support/users/bcrodua/)
 * (@bcrodua)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/#post-12574414)
 * Hi,
 * Apologies for the late reply.
 * I will consult our developer regarding this issue.
 * Thanks!
 *  Thread Starter [agenciesFirst](https://wordpress.org/support/users/agenciesfirst/)
 * (@agenciesfirst)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/#post-12577418)
 * Thank you for reply and stayed healthy everybody in these days.
 *  [Marc Lacroix](https://wordpress.org/support/users/marcusig/)
 * (@marcusig)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/#post-12581059)
 * Hi there,
 * I can’t reproduce the error on my Nginx setup, using the 2 plugins.
 * > when I click on plugin settings
 * Can you be more specific? Are you talking about WP-Optimize’s settings, or something
   else?
 * Marc.
 *  Thread Starter [agenciesFirst](https://wordpress.org/support/users/agenciesfirst/)
 * (@agenciesfirst)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/#post-12581837)
 * Hi, I understand why you can’t.
    EasyUpdateManager show in WP Backend following
   Message:
 * ———–
    “The following constants are set and will prevent automatic updates in 
   Easy Updates Manager.
 * Please check your wp-config.php file or other files for these constants and remove
   them to allow Easy Updates Manager to have control.
    WP_AUTO_UPDATE_CORE: This
   constant prevents automatic updates to new major releases of WordPress.” ———–
 * I clicked “dismiss” this message – and now WP-Optimize can show me the setting
   page. That is funny stupid ^^ – Sorry
 * WP error detection is not triggered now!
 * There is a tiny bug 🙂
 * Thanks
 *  [Marc Lacroix](https://wordpress.org/support/users/marcusig/)
 * (@marcusig)
 * [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/#post-12581881)
 * Ah yes, I was able to reproduce by adding that constant, so there is indeed a
   bug when those 2 plugins are installed and the constant is on. Thanks for pointing
   that out, we’ll fix it ASAP.
 * Marc.

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘Error while reading response header from upstream’ is closed to new replies.

 * ![](https://ps.w.org/wp-optimize/assets/icon-256x256.png?rev=1552899)
 * [WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance](https://wordpress.org/plugins/wp-optimize/)
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 * 5 replies
 * 3 participants
 * Last reply from: [Marc Lacroix](https://wordpress.org/support/users/marcusig/)
 * Last activity: [6 years, 1 month ago](https://wordpress.org/support/topic/error-while-reading-response-header-from-upstream/#post-12581881)
 * Status: resolved