After the last update the pages give a 404 error

I'm not a programming expert, after the last update of the theme, some pages that worked I can edit, modify and update, I put their url and when publishing them I go to that url and I get a 404 error, it is as if the template internally does not is able to find its own pages in the assigned urls. Any ideas or something I can edit internally in the template so that the theme finds the relationship between the page created with the template and the url without a 404 error? thx