Title: 404 errors on static files ( WPEngine ) Last modified: February 24, 2021 --- # 404 errors on static files ( WPEngine ) * Resolved [Viktor](https://wordpress.org/support/users/grnetfreak/) * (@grnetfreak) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/) * Hello Frank, * We’ve been seeing some random 404 errors on multiple static files on a site hosted @ WPEngine. From their end, they said they aren’t seeing anything “off”. Purging the cache makes it work, checking the logs, nothing specific seems to be triggering this. ( e.g. a new post published ) * Running WP 5.6.2 + Autoptimize 2.8.1 and with 404 fallbacks enabled of course. * Any ideas? Viewing 11 replies - 1 through 11 (of 11 total) * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14093857) * I’m assuming the static files you mention are Autoptimized CSS/ JS files? Can you test if the fallbacks work by taking the URL of an Autoptimized JS-file and changing one number/ letter in the hash (the random part of the filename), it should redirect to autoptimize_fallback.js? * frank * Thread Starter [Viktor](https://wordpress.org/support/users/grnetfreak/) * (@grnetfreak) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14096766) * Static files I meant are indeed the Autoptimize generated files! The fallbacks aren’t working: * I tried checking a CSS file autoptimize_164ccbfc71db096c97870abc99e0edd8.css – tried changing a letter or number near the end of the string, returns 404. * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14096791) * You’ll need to ask WPEngine to either: * have 404’s handled by WordPress * OR ensure 404’s for wp-content/cache/autoptimize/ get redirected to `/wp-content/ autoptimize_404_handler.php`, see example nginx configuration below * ``` location ~* /wp-content/cache/autoptimize/.*\.(js|css)$ { try_files $uri $uri/ /wp-content/autoptimize_404_handler.php; } ``` * Thread Starter [Viktor](https://wordpress.org/support/users/grnetfreak/) * (@grnetfreak) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14097504) * Thank you for the tip! WPEngine has added the code but now testing to see the filename change – I get a 410 error – I’ve enabled the error logging with the filter you have to monitor this! * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14097680) * 410 is when the fallback-handler does not find the fallback-file (wp-content/ cache/autoptimize/js/autoptimize_fallback.js), can you check if that exists? * additionally; 404 fallback only works when you’re serving the AO files as static files, this option is on by default but maybe you changed it? * Thread Starter [Viktor](https://wordpress.org/support/users/grnetfreak/) * (@grnetfreak) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14098194) * The autoptimize_fallback.js does exist and it’s accessible directly, but the 410 still exists. * And yeah, I have all but the last one ( shop cart/checkout ) options enabled at the Misc Options. ( I think that’s the default setup? ) * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14099271) * no idea I’m afraid .. can you share your site’s URL? * Thread Starter [Viktor](https://wordpress.org/support/users/grnetfreak/) * (@grnetfreak) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14103767) * Could I share it privately? I replicated the issue in another environment with same Autoptimize settings but without random 404 errors at the moment ( it was the same nginx rules you suggested ) – So it could be a WPEngine wide issue for the 404 fallback? * PS: I have Frank’s email from an old conversation * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 3 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14104641) * yes, it could be WP Engine wide; the basic issue is that normally WordPress handles 404’s, which AO hooks into. feel free to mail me 🙂 * frank * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 2 months ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14268192) * hey grnetfreak ; I’m not sure if I ever received your mail (maybe I did and I forgot)? 🙂 * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14479910) * No feedback so I assume this got resolved? Feel free to follow up if you still encounter issues! * have a nice day! frank Viewing 11 replies - 1 through 11 (of 11 total) The topic ‘404 errors on static files ( WPEngine )’ is closed to new replies. * ![](https://ps.w.org/autoptimize/assets/icon-256X256.png?rev=2211608) * [Autoptimize](https://wordpress.org/plugins/autoptimize/) * [Frequently Asked Questions](https://wordpress.org/plugins/autoptimize/#faq) * [Support Threads](https://wordpress.org/support/plugin/autoptimize/) * [Active Topics](https://wordpress.org/support/plugin/autoptimize/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/autoptimize/unresolved/) * [Reviews](https://wordpress.org/support/plugin/autoptimize/reviews/) * 11 replies * 2 participants * Last reply from: [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * Last activity: [5 years ago](https://wordpress.org/support/topic/404-errors-on-static-files-wpengine/#post-14479910) * Status: resolved