The main stylesheet is registered under the handle “thematic-main” and lives in the folder library/css/main.css. For some reason only the theme’s style.css is enqueued.
As I see the source code of the page, I notice the theme being referenced with the slug “Thematic-2.0” and not simply “thematic”. Since the theme is checking for the theme slug “thematic” in the enqueuing call, this is why the stylesheet is missing.
If you change the folder name to all lowercase “thematic”, things should work. This is same solution as the previous thread you created. Note that this only applies when the parent Thematic theme is the active theme.
In your child theme, all you need to add is
or use the supplied code in the sample child theme for the stylesheet to load. No matter the folder name of the parent.
That said, I would consider it a bug to require a hard coded folder name for the parent theme to work. I will make a note of it and fix it for a point release. Thank you for trying out 2.0 and reporting this.