Hi, I am receiving the ACK error on two of my three printers, all printers are the same model and configured identically. All three PlanetPress LPR queues are configured identically.

I referenced the older postings in this forum for this error but have not been able to resolve this issue.

Can you assist ?

What the error says is that the connection timed-out after sending the jobs because it never received the last ACK that confirm the end of transmission.

I would suggest rebooting all three printers and also check if you have network connection issues.