Mine turned out to be the same problem as above. But I don't understand how this could have happened, and it happens frequently. Something is always changing the password saved to the service, and I have to manually change it back to the right one. How could this have happened??!
Dag Stenkvist Dag, did this happen to you too? Thanks.
Mine is also a VM, Server 2008 R2, ArcGIS 10.3
It won't stop immediately after it's started though. It will be working fine. The problem is only at each startup -- the password will have to be changed...!!