This is probably due to a missing middleware in Traefik, which causes problems for Odoo 16. The traefik.http.middlewares.odoo-header.headers.contentSecurityPolicy=upgrade-insecure-requests​ label configures a middleware called "odoo-headers" to enforce the Content Security Policy header with the value "upgrade-insecure-requests". This header instructs the browser to upgrade any insecure HTTP requests to HTTPS before making the request. The traefik.http.routers.odoo.middlewares=odoo-headers​ label associates the "odoo" router with the "odoo-headers" middleware, which will process requests caught by the router to upgrade insecure requests. You can check out my blog post how to setup Traefik for Odoo (I have configured many Odoo instances with this configuration):  Setting up a reverse proxy for Odoo with Nginx Proxy Manager in Docker.

I hope this helps!

Has anyone found a solution to this problem? https://github.com/odoo/odoo/issues/104597

look at this https://github.com/odoo/odoo/issues/104947

The "Mixed Content" error typically occurs when you are serving content over both HTTP and HTTPS. This can happen when you have SSL enabled on your website but some of the resources are still being loaded over HTTP.

In the case of Odoo + Traefik + SSL, this error could occur if you are using the Odoo editor to edit your website and some of the resources (such as images or scripts) are being loaded over HTTP instead of HTTPS.

To resolve this error, you will need to ensure that all resources on your website are being served over HTTPS. Here are some steps you can take to fix this issue:

1. Check your website for mixed content errors: You can use a tool like the "Why No Padlock?" tool to check for mixed content errors on your website. This tool will scan your website and identify any resources that are being loaded over HTTP instead of HTTPS.

2. Update Odoo configuration to use HTTPS: You need to update Odoo configuration to ensure that all resources are being loaded over HTTPS. You can do this by modifying the "base.url" parameter in the Odoo configuration file to use HTTPS. You can find the configuration file in the Odoo installation directory.

3. Update Traefik configuration to use HTTPS: Similarly, you will also need to update Traefik configuration to ensure that all resources are being served over HTTPS. You can do this by modifying the Traefik configuration file to use HTTPS.

4. Update website content: If you still have mixed content errors after updating Odoo and Traefik configuration, you will need to update your website content to ensure that all resources are being loaded over HTTPS. This may involve updating links to resources and ensuring that any custom scripts or stylesheets are being loaded over HTTPS.

Once you have resolved all mixed content errors on your website, the "Mixed Content" error should no longer occur when using the Odoo editor.

same Problem here.

Working with ngnix proxmanager instead of traeffic but still the same problem.
Great to see that nobody cares... ;-(

I had the same issue and continue until now searching how can I fix it