I have a page view("/news") with contextual filter for the topics ("news/design","news/coding"...) which are taxonomy terms and this worked fine. Due to some changes for the mobile theming, I need a block view instead of the page view, but I can't get it to work with the filters.
With the old filter settings I get all my articles in "/news", but the filter I am using changed the default value from the filter to "taxonomy term ID from url"; I now see an empty page for "/news" (this is now a simple page with the block view included) and a "site not found" for "/news/design" etc. In the preview of the view, everything works fine.
These are the settings for the view.