AuthenticationException

Example

{
	"code": "AuthenticationException",
	"target": "Unknown",
	"details": [
		{
			"code": "AuthenticationException",
			"number": 30,
			"message": "Authentication failed.",
			"description": "Unable to authenticate the user or the account.",
			"faultCode": "Client",
			"helpLink": "http://developer.avalara.com/avatax/errors/AuthenticationException",
			"severity": "Exception"
		}
	]
}

Explanation

This error message indicates that the username and password you provided could not be found. Common troubleshooting steps:

Have you forgotten to Base-64 encode your username+password?
Have you mistyped your username or password?
Are you attempting to authenticate against the sandbox server when you intended to use the production server, or vice versa?