I am trying to build a simple Owl component in Odoo 18 to learn how Owl and QWeb work together.
When I open my custom page (for example: http://localhost:8069/awesome_owl), the page loads but shows the following warning:
“A CSS error occurred using an old style to render this page.”
I am not using Bootstrap or any third-party CSS. My __manifest__.py file looks like this:
'assets': {
'web.assets_backend': [
'awesome_owl/static/src/scss/playground.scss',
],
'awesome_owl.assets_playground': [
# 🧠 Odoo core helpers and JS framework
('include', 'web._assets_helpers'),
('include', 'web._assets_core'),
# 🦉 Your custom Owl files
'awesome_owl/static/src/playground.js',
'awesome_owl/static/src/playground.xml',
'/awesome_owl/static/src/scss/playground.scss',
],
},
And my XML template:
<template id="awesome_owl.playground" name="Awesome Owl Playground"> <html> <head> <t t-call-assets="awesome_owl.assets_playground"/> </head> <body> <div id="awesome_owl_root"></div> </body> </html> </template>
The SCSS file is simple and contains custom styles only.
Despite this, Odoo still throws that CSS rendering error.