Scenario: You have a VPS, you have installed Apache, MySQL, PHP and WOrdpress, and you want to enable pretty permalinks. If you're getting a 404 error when accessing your WordPress posts after having enabled pretty permalinks in the settings, then this is how to solve the issue (at least it worked for me).
Log in into your VPS server.
then let's get to the sites-enabled folder
Here there is a file called 000-default
using something like nano (a simple text editor) open this file
(sudo) nano 000-default
Use sudo if you're not logged in as root.
Now that the file is open, you'll see something like this:
DocumentRoot /var/www Options FollowSymLinks AllowOverride None Options Indexes FollowSymLinks MultiViews AllowOverride None Order allow,deny Allow from all
What we need to do is to change those two "AllowOverride None" to "AllowOverride All". Like so:
DocumentRoot /var/www Options FollowSymLinks AllowOverride All Options Indexes FollowSymLinks MultiViews AllowOverride All Order allow,deny Allow from all
Once it's done, just restart your apache server
And your pretty permalinks should be working now! Nice!