This error is caused when the IP Address changes on the PAX EMV device.
Go into MicroSale in the Pax setup; if you know the IP address of the Pax unit you can just type it in the field that says ‘IP Address’ and save it.
Or, MicroSale will find it for you by going to Managers Menu > Register Setup > Terminal Configuration > Credit Card Setup > Pax > Find Device. Save when finished.