Receiving a "service '?' unknown" or "service 'sapmsxxx' Unknown" error message when attempting to connect to a Message Server.
This issue is often caused by a missing sapmsXXX entry in the \WINDOWS\SYSTEM32\DRIVERS\ETC.\SERVICES file.
Edit the file \WINDOWS\SYSTEM32\DRIVERS\ETC.\SERVICES and add the following line to the end of the file updating the PRD and 3600 values as noted below. NOTE: Be sure to click the Enter key after the entry so it looks like the last line is blank.
Update the 2 bolded fields with the following:
PRD: System ID of the Message Server
3600: Port Number