You sure can do it manually. I am trying to find out why the page is blank too, but in the mean time I have manually altered the setting in PHPMyAdmin.
1. Go in to PHPMyAdmin
2. In the sidebar on the left select wp_options
3. Go to Page number: 2
4. click the pencil on the link with permalink_structure
5. In the big box next to option_value and input /%postname%
It works on my site https://www.desirableweddings.com/backyard-weddings
