error /page/2/

Faced such a problem, please help to solve it. I'm using WordPress. I do not have page navigation on my site (1,2 Next), when I click on the page with entries for "2" or "Next", then go to site.ru/page/2/ and the page gives an error: "Page not found". When you set up permanent links when you select "Simple", the next page with entries works and the entries are displayed when I click on "2" or "Next", and if you select "Arbitrary" and /% category% /% postname% / does not work and writes "" Page not found. " How do I configure the display of the following entries on the second page when /% category% /% postname% /?