Symptoms
• Work processes start but no logins are possible.
• Users get the login screen but the system does not log them in. Instead, they get this error: No logon possible (no hw ID received by mssg server).
• In the SAP MMC, the message server (msg_server.exe) shows status "stopped".
• The dev_ms file reports these errors:
[Thr 2548] *** ERROR => MsCommInit: NiBufListen(sapmsTST) (rc=NIESERV_UNKNOWN) [msxxserv.c 8163]
[Thr 2548] *** ERROR => MsSInit: MsSCommInit [msxxserv.c 1561]
[Thr 2548] *** ERROR => main: MsSInit [msxxserv.c 5023]
[Thr 2548] ***LOG Q02=> MsSHalt, MSStop (Msg Server 2900) [msxxserv.c 5078]
Problem Analysis
Work processes were able to start but the message server was not. The reason is because the "services" file is missing the SAP System Message Port entry. Example: SAPmsTST 3600/tcp
Solution
Edit the "services" file and add the entry. Then, re-start the instance. Make sure you specify the appropriate TCP port (e.g. 3600) for the message server.