Effective Apr. 2016 Kaseya will no longer support the installation of AuthAnvil Two-Factor Auth, Single Sign On or Password Server on the same IIS web server as Kaseya VSA.
This change is due to the addition of KAF (Kaseya Application Firewall) for Kaseya VSA that was added in R7.
For more information about KAF please see this article.
To prevent any port conflicts you will need install AuthAnvil on a server that does not have Kaseya installed on it.
Note: This issue only affects the IIS website installation not the database location.