Wordpress seems to be ignoring page.php, how to understand why?

Question

WordPress

Good evening! I ask everyone who can have at least some ideas about the following problem to respond: the site worked in the morning, installed the comfortable reading plugin in the afternoon, everything worked. I left for 2 hours, went to the site - all posts and page content were no longer displayed. It seems that WP ignores page.php, since any edits, attempts to remove pieces of code and understand where the error did not lead to success, nothing happens. That is, for example, I click on any link, or the main menu item, it goes to the page, in the address bar of the page url, but only the normal sidebar is displayed, and the page content and the sidebar for this page should be displayed. Perhaps the soap of information, I just have not come across this before. I look forward to your responses..

Answer 1

Permalinks update helped (console-settings-permalinks)