Title: Console error: Uncaught SyntaxError: invalid escape sequence. Last modified: February 26, 2026 --- # Console error: Uncaught SyntaxError: invalid escape sequence. * Resolved [anne-marie mumford](https://wordpress.org/support/users/anne-marie-mumford/) * (@anne-marie-mumford) * [3 months, 1 week ago](https://wordpress.org/support/topic/console-error-uncaught-syntaxerror-invalid-escape-sequence/) * When I try to update from 4.0.11 to 4.0.12 or 4.0.16 (and a few others I’ve tried in-between), the snippets don’t work anymore. I get an error in the console ‘ Uncaught SyntaxError: invalid escape sequence.’ [I have PHP, HTML and JS snippets]. I’ve been waiting before I post about the issue as this type of thing usually gets sorted in a next update, but I’m still getting the issue quite a few updates in, and while for 4.0.11 ‘don’t click links you are sent’ is a pretty good deterrant in the meantime for this vulenrability for the admins, it’s a vulnerability I’d like to remove.I just want to make sure this is an issue you’re aware of and is still in the progress of being sorted.If any more details would be helpful for the issue, let me know.In the meantime, thanks for the awesome plugin, it’s been a great help for a long time! - This topic was modified 3 months, 1 week ago by [anne-marie mumford](https://wordpress.org/support/users/anne-marie-mumford/). - This topic was modified 3 months, 1 week ago by [anne-marie mumford](https://wordpress.org/support/users/anne-marie-mumford/). Viewing 7 replies - 1 through 7 (of 7 total) * Plugin Support [muddasirhayat](https://wordpress.org/support/users/muddasirhayat/) * (@muddasirhayat) * [3 months, 1 week ago](https://wordpress.org/support/topic/console-error-uncaught-syntaxerror-invalid-escape-sequence/#post-18835588) * Hi [@anne-marie-mumford](https://wordpress.org/support/users/anne-marie-mumford/), * Thank you for reporting this and for the detailed explanation. We really appreciate you taking the time to test multiple versions before posting. * The `Uncaught SyntaxError: invalid escape sequence` error is typically related to how certain characters are being parsed in JavaScript, and it may be triggered by specific snippet content or changes introduced in recent updates. * We like to investigate this further to identify the exact cause. * Could you please provide: - The WordPress version you’re currently running - Your PHP version - An example snippet (or a simplified version) that breaks after updating - Confirmation whether the issue occurs with all snippets or only specific ones * If possible, also let me know whether the issue persists with all other plugins temporarily disabled and a default theme activated. This will help rule out conflicts. * Thank you for your patience while we look into this. I’ll do my best to resolve it as quickly as possible. * Best regards, WPExperts Support Team * Plugin Support [muddasirhayat](https://wordpress.org/support/users/muddasirhayat/) * (@muddasirhayat) * [3 months ago](https://wordpress.org/support/topic/console-error-uncaught-syntaxerror-invalid-escape-sequence/#post-18841337) * Hi [@anne-marie-mumford](https://wordpress.org/support/users/anne-marie-mumford/), * Thank you for your detailed explanation and for your patience. * The issue you described — specifically the console error **“Uncaught SyntaxError: invalid escape sequence”** affecting PHP, HTML, and JS snippets after updating from 4.0.11 — was related to how certain characters were being processed in newer versions. * Our team has identified the root cause and released a new version that resolves this behavior. * Please update to the latest version and clear your browser/site cache before testing. The snippets should now execute correctly without triggering the console error. * We also appreciate your concern regarding the vulnerability in 4.0.11 — updating to the latest version is strongly recommended to ensure both functionality and security. * Thank you * Thread Starter [anne-marie mumford](https://wordpress.org/support/users/anne-marie-mumford/) * (@anne-marie-mumford) * [3 months ago](https://wordpress.org/support/topic/console-error-uncaught-syntaxerror-invalid-escape-sequence/#post-18841622) * Thanks for the quick update! I’ll test the new version tomorrow 🙂 * Thread Starter [anne-marie mumford](https://wordpress.org/support/users/anne-marie-mumford/) * (@anne-marie-mumford) * [3 months ago](https://wordpress.org/support/topic/console-error-uncaught-syntaxerror-invalid-escape-sequence/#post-18843306) * The newest version 4.0.17 is changing the javascript/jQuery quotes and apostrophes in the JS post snippets to escaped \’ and ", and new line breaks are being converted to \n, and that’s how it’s being output to the page, which is breaking the code, and giving the console error: `Uncaught SyntaxError: invalid escape sequence` Rolling back to the 4.0.11 version this issue isn’t present.Example snippet with the error:jQuery( ‘.frb_button’ ).on( ‘mouseenter’, function() { var color = jQuery(this).attr(‘data-hovertextcolor’); var bgcolor = jQuery(this). attr(‘data-hoverbackcolor’); jQuery( this ).css( {“background-color”: bgcolor,“ color”: color } ); } );With 4.0.17 in the console it turns into: * ```wp-block-code jQuery( \'.frb_button\' ).on( \'mouseenter\', function() { var color = jQuery(this).attr(\'data-hovertextcolor\'); var bgcolor = jQuery(this).attr(\'data-hoverbackcolor\'); jQuery( this ).css( {"background-color": bgcolor, "color": color } ); } ); ``` * Whereas in 4.0.11 when I look in the console, it looks as it does in post-snippets( no escaping). I think it’s only the JS snippets that are having this problem, that start in the code editor with the premade