Page Not Found - other causes

Errors and Error Messages
If you receive the Page Not Found error - it can also be related to your Web.Config's "connectionString" parameter if you changed SQL user name to be used by EP to a custom one from "sa".

EP needs to access two SQL databases (via sql user id you supplied during setup): 1) the EP db and 2) the "ASPState" db.
Both are setup during the EP installation process and should be accessible for EP to work.

Here we assume that you have left the default option to store a session chosen during the EP installation.

You should setup persistent session storage mode for the "ASPState" database.
 Please refer the bottom of this KB article on how to install it: