Issue Running Both WWW & Non-WWW And Multiple Contexts

I am running two websites from a single install of Revo. Currently for both sites I have the site URL and http host as the non-www URL.

Visitors to www. are getting a 404 error.

How can I run all four domains (two domains in both www and non-www) correctly?

It generally a good idea to pick one or the other and stick with it. There is commented-out code in .htaccess to automatically move any visitors to the preferred option. That means that the site can be reached with either URL, but once the user is inside, they'll stay in the one you picked in .htaccess.

If you don't do that, you'll lose all the $_SESSION data if a user switches from a www page to a non-www page.