Any event with the source "EMONSVC" relates to TNT Software's ''Event Log Monitor'' software. This is the source name of their agents deployed to the monitored system(s).
Service SAP Front-End Distribution Service is stopped - In my case, the server which had the error was a SAP Distribution Server, used to distribute packages through an administrative setup to client workstations on the network. The service itself was using a domain-account instead of the local system account on the server. I changed the service to (log on with) local system and once I restarted the service, the problem was solved. Generally, I believe that almost every 900 event is caused by a service, which uses the wrong account to enable or start a service because the account has insufficient permission, is locked out or disabled.