Event ID 1306 is the result of an invalid token sent to the authentication system. Basically, it means the credentials sent by the workstation to the proxy could not be validated against the domain(s).
Most likely reasons for this event to be generated include :
Troubleshooting tips :
In the example above, if the Java request was answered by a 401 (Authenticate) or a 407 (Proxy Authenticate), the application might not have been able to provide credentials, in which case, the connection would be denied and the 1306 message would be generated in the BCAAA server's event log.