Fix critical Odoo web editor error (jQuery - Malformed selector: ", .o_newsletter_popup")

Job ID: 40302495

Budget: €8 – €30 EUR

Project Description:

I need an Odoo specialist (Community/Enterprise version) to fix an error that prevents the web editor from working properly.
The Problem:

When trying to edit any website page in Odoo, the following error appears on screen:
text

Odoo Client Error
UncaughtPromiseError > OwlError
Caused by: Error: Syntax error, unrecognized expression: , .o_newsletter_popup

The error occurs specifically in the Owl lifecycle (onWillStart) of the WYSIWYG editor and is related to a malformed jQuery selector that starts with a comma (", .o_newsletter_popup").
What I've already tried:

Cleared browser cache

Updated modules (web, website, web_editor) with -u

Verified it's not a version issue (I do NOT want an upgrade to a major version, just maintain my current version)

Technical Environment:

Server: Linux (probably Ubuntu/Debian)

Access: Via AnyDesk to my local PC, then SSH to the server from there

Odoo installation method: [INDICATE HERE IF .deb, GIT, DOCKER, etc.]

Important - Security:

I will NOT share passwords through the platform

Credentials will be provided via private chat ONCE the project is accepted

The connection will be monitored throughout the entire process

Requirements:

Connect via AnyDesk to my PC (I'll provide ID and temporary password)

From there, access the server via SSH

Diagnose the root cause of the error (likely a custom module or DOM conflict)

Implement a permanent fix

Verify that the web editor works correctly

Required Skills:

Odoo expert (specifically in web_editor and Owl framework)

Advanced JavaScript/jQuery knowledge

Linux server and SSH experience

Experience debugging Odoo