The scenario is that you restore you files and database to a new host and then when you access the dashboard (as well as the front end) you see no posts. They are listed i.e. All (nnn) Published (x) Draft (y), but there are none displayed.
Equally, you upgraded the current server to a new version and this upgrades the php version.The site may work (with blank list of posts) or the site may break and the frontend or administration cannot be accessed.
We had this and for us it was a very stale plugin that should have deleted years ago (Psychic Search) !.
If this happens to you and you have back-end access to the administration interface then deactivate all plugins that are old until the site comes back correctly.
If the site is so broken that you do not have access to the administration interface then you can use FTP to go to wp-content/plugins and then go through the change date and from the oldest dated plugin, download it (to take a backup) and then delete the plugin. When WordPress tries to load the now-deleted plugin then it can’t and the plugin becomes deactivated. This should get you back into the site and you can then use the administration interface to either install a updated version of the broken/obsolete plugin or an equivalent that does have support for your host/php version.