Title: Uncaught Reference Error Last modified: July 8, 2020 --- # Uncaught Reference Error * Resolved [hsrothbard](https://wordpress.org/support/users/hsrothbard/) * (@hsrothbard) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/) * Hello! I have Optimize JavaScript Code checked, but Aggregate JS Files unchecked. I am receiving the following errors. Uncaught ReferenceError: jQuery is not defined at jquery-migrate.min.js:2 * Uncaught ReferenceError: jQuery is not defined at jquery-ui.min.js:14 * Uncaught ReferenceError: jQuery is not defined at autoptimize_single_f883f55850533be9166b11cf241de0a9. js:1 * Uncaught ReferenceError: jQuery is not defined at autoptimize_single_309e1a27ab5c8722dea8f46fc8c384d5. js:20 * Could you please suggest a fix for this. * Thanks for your time!! * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Funcaught-reference-error-4%2F%3Foutput_format%3Dmd&locale=en_US) to see the link]_ Viewing 9 replies - 1 through 9 (of 9 total) * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13098405) * just tested in Firefox & Chrome and don’t see such error hsrothbard, so maybe you fixed it already? * frank * Thread Starter [hsrothbard](https://wordpress.org/support/users/hsrothbard/) * (@hsrothbard) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13101192) * Hello Frank! * Yes.. it is fixed. I went to sleep and when I tested again, the error no longer appeared. I wish ALL my issues were that easy to solve!! * I have an idea it was from me experimenting. I know I am not tapping into the full potential of Autoptimize.When I enable aggregate js files, it breaks my menu and actually slows down the site. So I am trying to tap into the async option. * Lighthouse testing results to eliminate render blocking resources- //ajax.googleapis. com/ajax/libs/jqueryui/1.5.3/jquery-ui.min.js * //www.wallpapergeeks.com/wp-includes/js/jquery/jquery-migrate.min.js * //www.wallpapergeeks.com/wp-includes/js/jquery/jquery.js * //www.wallpapergeeks.com/wp-content/cache/autoptimize/css/autoptimize_7b3695e98283d84e6e4cdd25ca325681. css * wp-content/cache/autoptimize/js/autoptimize_single_f883f55850533be9166b11cf241de0a9. js * I wish I was more knowledgable, but I am learning. I am leery to keep testing as not to encounter another problem. Any and all suggestions are so welcomed. * Thanks again…. * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13101494) * you should _probably_ be able to async jquery-ui, jquery-migrate and the autoptimize_single one. jquery can rarely be asynced really. * for the CSS you can try the “inline & defer CSS”-option, there’s more info in [the AO FAQ](https://wordpress.org/plugins/autoptimize/#faq). * frank * Thread Starter [hsrothbard](https://wordpress.org/support/users/hsrothbard/) * (@hsrothbard) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13102699) * That’s what I call excellent support!! Thanks for your quick response and suggestion. Autoptimize has now proven it’s worth. I have made strides in lighthouse and GTmetrix but have more to go. * I get more ideas from GTMetrix to defer.Can I async as much as possible or is this counterproductive? Some results below- wp-includes/js/wp-embed.min.js wp- content/themes/PixatoLight/assets/javascripts/adapt.min.js * Do you have any recommendation to optimize .jquery? * I have been testing inline & defer CSS. I generated critical path CSS. Do I use the minified or unminified, or the minified or unminified combined? * Truly appreciate your support- * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13103332) * you can async as much as you want, only limitation things might break, so always test. * re. jquery; you’ll probably have to leave that be. * re. critical CSS; have a look at [https://www.youtube.com/watch?v=k56E_7SFQoE](https://www.youtube.com/watch?v=k56E_7SFQoE)( not my video) 🙂 * Thread Starter [hsrothbard](https://wordpress.org/support/users/hsrothbard/) * (@hsrothbard) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13106217) * I don’t see the aggregated file in my code, just the individual style sheets. What am I missing? * Thread Starter [hsrothbard](https://wordpress.org/support/users/hsrothbard/) * (@hsrothbard) * [5 years, 11 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13106227) * Sorry,found it! I couldn’t see it is Safari, but found it in Chrome. * Thread Starter [hsrothbard](https://wordpress.org/support/users/hsrothbard/) * (@hsrothbard) * [5 years, 10 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13169629) * Hello!! * Inline and Defer CSS worked great. Thank you. * I have been testing different scenarios. * I have moved some CSS above JS. Strange, it helped with performance in lighthouse and CLS slightly, but hurt LCP. Should I generate new critical path CSS? * I removed Google Fonts instead of combining and preloading as there was a strange tick where the fonts went from thick to thin.Now they load bold.Is there a way to change that? Should I no longer prefetch fonts.googleapis.com or fonts.gstatic. com? * wp-content/cache/autoptimize/js/autoptimize_single_f883f55850533be9166b11cf241de0a9. js is not asynced even though it is listed. Am I doing something wrong? * There is an error when loading in lighthouse- GET [https://www.wallpaprgeeks.com/asset-manifest.joson](https://www.wallpaprgeeks.com/asset-manifest.joson) 404 It goes away, but is this something I can/should fix? * I get a message to preload wp-content/themes/PixatoLight/assets/stylesheets/unsemantic- grid-tablet.css but when I do, I sometimes get a warning message loaded but not used. * Thanks so much for all your support. * Plugin Author [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * (@optimizingmatters) * [5 years, 10 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13169829) * > Should I generate new critical path CSS? * no * > Now they load bold.Is there a way to change that? * you’ll have to change the CSS somewhere .. :-/ * > Should I no longer prefetch fonts.googleapis.com or fonts.gstatic.com? * indeed, not needed. * > wp-content/cache/autoptimize/js/autoptimize_single_f883f55850533be9166b11cf241de0a9. > js is not asynced even though it is listed. Am I doing something wrong? * that’s JS that is excluded from optimization, adding it to async does not work, you’ll have to add the original filename * > There is an error when loading in lighthouse- > GET [https://www.wallpaprgeeks.com/asset-manifest.joson](https://www.wallpaprgeeks.com/asset-manifest.joson) > 404 It goes away, but is this something I can/should fix? * no idea what that is I’m afraid. * > I get a message to preload wp-content/themes/PixatoLight/assets/stylesheets/ > unsemantic-grid-tablet.css > but when I do, I sometimes get a warning message > loaded but not used. * I would simply ignore that 😉 Viewing 9 replies - 1 through 9 (of 9 total) The topic ‘Uncaught Reference Error’ 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/) * 9 replies * 2 participants * Last reply from: [Optimizing Matters](https://wordpress.org/support/users/optimizingmatters/) * Last activity: [5 years, 10 months ago](https://wordpress.org/support/topic/uncaught-reference-error-4/#post-13169829) * Status: resolved