Title: Browser errors Last modified: May 14, 2020 --- # Browser errors * Resolved [AmDev1](https://wordpress.org/support/users/amdev1/) * (@amdev1) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/) * Hi I’ve recently installed Autoptimize with a new theme and love it! I have a handful of issues/opportunities reporting in GPSI and hope you can help me work out which are important and how I might fix them. I’ll list them here: Browser errors were logged to the console (x2) Does not use passive listeners to improve scrolling performance Remove unused CSS * Thanks for any help you can offer Angela * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fbrowser-errors-2%2F%3Foutput_format%3Dmd&locale=en_US) to see the link]_ Viewing 7 replies - 1 through 7 (of 7 total) * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835070) * Hey AmDev1; 1. I don’t see browser errors on the console, does GPSI specify anything? 2. passive listeners are not autoptimize’s thing, those will be used by one of the original JS-files AO combined 3. The unused CSS is being reported as being Autoptimize’s, but AO merely aggregates all the CSS provided by your theme & plugins, so if you (really) want to tackle “remove unused CSS” then you should look into your theme & plugins (you might be able to get some improvement using e.g. “plugin organizer” to only allow plugins to work on specific pages). Moreover the unused CSS will likely be different for different pages (or parts of your site), so that would lead to different autoptimized CSS-files being loaded on different pages. * hope this clarifies, frank * Thread Starter [AmDev1](https://wordpress.org/support/users/amdev1/) * (@amdev1) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835349) * Thanks for quick response Frank On the browser errors GPSI shows the urls [https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js](https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js) with a description: ReferenceError: jQuery is not defined at Object.parcelRequire. b9JU../fn/add-missing-icons ([https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:7606](https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:7606)) at f ([https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:468](https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:468)) at parcelRequire.BvyT ([https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:771](https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:771)) at [https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:1023](https://mowgli-adventures.com/wp-content/cache/autoptimize/js/autoptimize_single_56cd2313818653301310cffe75b98ed9.js:1:1023) * It shows this twice. * Thanks again Angela * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835373) * ah “jQuery is not defined”, in that case you’ll have to exclude jquery (`plugins/ jquery-updater/`) from JS optimization. * Thread Starter [AmDev1](https://wordpress.org/support/users/amdev1/) * (@amdev1) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835568) * Ok thanks So the question is which error is better? * Includes front-end JavaScript libraries with known security vulnerabilities ( which I get when I switch off the jquery updater) or browser errors on the console. * What do you think? Regards * Angela * Thread Starter [AmDev1](https://wordpress.org/support/users/amdev1/) * (@amdev1) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835606) * Ignore me – that was a daft question. I’ve resolved it as you suggested. Thank you! Angela * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835642) * no worries 🙂 * but re “Includes front-end JavaScript libraries with known security vulnerabilities”; the wordpress.org actually backport security fixes, so there _should_ not be security vulns. 🙂 * Thread Starter [AmDev1](https://wordpress.org/support/users/amdev1/) * (@amdev1) * [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835667) * Good to know – thank you again Viewing 7 replies - 1 through 7 (of 7 total) The topic ‘Browser errors’ 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/) * 7 replies * 2 participants * Last reply from: [AmDev1](https://wordpress.org/support/users/amdev1/) * Last activity: [5 years, 12 months ago](https://wordpress.org/support/topic/browser-errors-2/#post-12835667) * Status: resolved