I have just upgraded from gms14 (Latest service patch) to gms18. Everything worked as expected (upgraded postgresql and did the certificates) and at the same time upgraded from sles11sp4 to sles12 sp2. All the services appear to start correctly, but when I log into the admin, I get a message illegal server error. Anyone got any ideas where I went wrong or how to correct this problem. I an start and stop gms with no problems and everything starts up as expected.