Hi @supersharp
The process has two steps: install Java 11, then point KNIME Server to it.
For Windows, we recommend this Java installation: Adoptium - Open source, prebuilt OpenJDK binaries
By default, it will install in C:\Program Files\Eclipse Adoptium\jdk-<version> (can be changed during installation).
On Linux, you can grab Java from your package manager, e.g. sudo apt install openjdk-11-jdk. Often it is installed to /usr/lib/jvm/java-<version>.
To point KNIME Server to the correct Java version, you’ll want to edit the file <knime_server>/apache-tomcat-<version>/bin/setenv.bat|.sh (.bat for Windows, .sh for Linux): Simply point the JAVA_HOME variable to the new Java 11 installation. On Linux, the JAVA_HOME environment variable may also be set in the service, see (sudo) systemctl edit knime-server.
Kind regards
Marvin