I had a similar issue, and found out that it was related to two things.
DNS Servers - the printer may be trying to access the server without being pointed to the correct DNS server. Domain Name - the printer is not part of the domain and the authentication system thinks the printer is trying to compromise the network.
I had this issue with a NAS, all I did was give it one DNS Address (the server IP) and I made sure it was part of the domain.
Not sure if this will help.