How to enable the language Server?

[lubber-de]

I cannot seem to get the language server work.
I setup everything but live compilation on source change does not start, thus there never are any error messages in the problem tab. It only compiles when called explicitely via command. And only then the problem tab is never filled by anything. It only shows the first occuring error in the output tab.
Also hovering over labels, literals, mnemonics does not do anything.
What is the language server (implemented since 1.3 according to changelog) actually doing or what am i doing/expecting wrong?

I am using KickAss 5.11 and latest vscode 1.41 as well as openjdk 1.3 and Windows 10

[CaptainJiNX]

Sorry, I never got a notification for this. Probably had those turned off...
Anyway, I tried the language server only on Mac OS, and for me it works fine with KickAss 5.12
Not so sure about the openjdk tho, but when I run java --version on my machine i get this response

openjdk 12.0.2 2019-07-16
OpenJDK Runtime Environment AdoptOpenJDK (build 12.0.2+10)
OpenJDK 64-Bit Server VM AdoptOpenJDK (build 12.0.2+10, mixed mode)

It was my friend that said it worked on Windows 10. But maybe I should take some time and test it there as well.
Could it be some java paths that are configured wrong perhaps?