Lmadmin 11.14, Windows Server 2012 R2 and Windows Server 2012 - an experience I had
Just want to log this in case this comes up with anyone else. I had a rare situation where a working 11.14 license server was upgraded from Windows Server 2012 Standard to Windows Server 2012 R2 Standard. All the installed apps on the server were qualified for the R2 release, including the FlexLM server, according to "Hardware Notes – PTC License Server Last updated: November 22, 2017" from PTC.
After running the R2 upgrade, everything came back except lmadmin. "ptcstatus" gave “System error 10061 ‘WinSock: Connection refused”, indicating the daemon was not running. Sure enough, not only was it not running, but the Windows service "lmadmin" was missing from the Services list.
The remedy was to uninstall and re-install the license server. That was the only way to re-install the service, according to "License Administration Guide FlexNet Publisher Licensing Toolkit 11.10.1", which recommends running lmadmin as an OS service.

