The /category/ and /tag/ pages is working fine. But /category/*** sub-pages show 404 error and basically the blog generates no category page.
How do I fix this problem?
Jekyll doesn’t generate category / tag pages out of the box.
You need to have a plugin implemented for that.
Additionally. GitHub Pages doesn’t allow third-party plugins to be loaded in its environment.
Therefore, if you’d like to continue using GitHub Pages to deploy your site, the only solution is to manually include a file for every category / tag in your site.
For example,
create file at path pages/categories/life.html or <..>/life.md