Updating a wordpress site
A period of 30 days is enough to gather a nice package of updates for various plugins and Word Press itself.
The first thing I do is I go to https://codex.wordpress.org/Updating_Word Press, and make sure that there are no new items on the list since my previous update.
If you have not tried reading through the Word Press 4.8 master list for Fixing Word Press.
If you're still having the issue, try re-loading the core files for Word Press or discussing the issue within the Word Press support forum.
Now that files, pages and posts are backed up, it is time to backup your Word Press database. Once you complete all these steps, it’s time to proceed forward.
The easiest way to update Word Press is by using the Automatic Update which works great for most people.
To launch automatic update, click on the link in the new version banner at the top or go to Dashboard Upgrade menu.
I mean, it most likely is one of the best ways of performing an update, but in most cases it’s not doable for a normal human being.
OK, the first thing the Codex tells you to do is to make sure that your server meets the requirements, and this I do. Or in plain English – what needs to be installed on your web server for it to be able to run Word Press.
If you are using a Word Press default theme Twenty Eleven or Twenty Twelve theme, then your theme will also be updated when you update Word Press.
Make sure to backup your theme if you have made any customizations or else those changes will be lost.