The sessions folder has been introduced in 5.3 and the Upgrading from 5.2 to 5.3 documentation page doesn't have any mention to that.

This generates authentication issues, and users will not be able to log in to the site.

A "Setting up folder permission" step like the one on the installation instructions page (only the 5.3 part) should be included in the Upgrading from 5.2 to 5.3 documentation page.