I think we were running 1.8.0_191. We reinstalled the webserver, selected this version of Java and the webserver was running again.
1) As a test I installed a new EMSC on a new Server2016 environment, running java 1.8.0_231. That also installed correctly.
2) On another existing server 2016 environment, running Java 1.8.0_144 and 1.8.0._171, I manually updated Java to the newest 1.8.0_231 version. The installer recommended uninstall of the 144 version, which I did. After that, the ESMC webconsole still worked (also after a reboot of the windows server).
My conclusion would be, that is has nothing to do with Java.
On this Server 2016 environment, there were some Windows Updates ready to be installed (.NET updates KB4519562 and KB4524095). I did these updates and rebooted the server. Still working.
So I think we can rule those updates out too.