On the AuthAnvil server, open a browser and navigate to http://localhost/AuthAnvilSAS/SAS.asmx. Click on "Authenticate" and put in your AuthAnvil Username, your next Passcode, your Site ID, and a Tokentype of 1 and click test. This will give you a detailed exception which can be checked against the Knowledge Base.
If you have any questions or need some help, we would be happy to assist. Open a case at kaseya.zendesk.com .