The screen of the Printer shows an error trying to login:
Siteapp.log will show a similar message to below:
[ERROR] 2021-04-01 16:19:58.891 {82539} MobileGatewayActionInterface5_0 - Printer with device serial: ABCD not found!
com.nps.eopng.mid.terminalandmobile.mobileprint.error.PrinterUnknownException: Printer with device serial: ABCD not found!
Resolution:
Ensure that the printer serial number has been entered when adding the printer to HCP