Why won't eclipse oxygen start (for the first time)? [duplicate]

Answer 1

To run Eclipse with Java 9 you need to modify the 'eclipse.ini' file in your Eclipse installation and add the line:

--add-modules=java.se.ee

as a line following the -vmargs line in the file. This adds the Java 9 module containing the missing classes.

You can also use

--add-modules=ALL-SYSTEM

See Eclipse Wiki: Configure Eclipse for Java 9.

Eclipse Oxygen.1a (4.7.1a) is due to be released on 11 October (2017) with full Java 9 support.

Answer 2

Java 9 has some subtle changes that large programs tend to have problems with. Eclipse has issues both with running under Java 9 and using Java 9 as the Java Runtime Environment in the Workspace.

Until a official version of Eclipse supporting Java 9 comes out (apparently at October 11th), non-power users may have a better experience by downgrading to Java 8.

Answer 3

Your eclipse.ini should contain something like:

--launcher.appendVmargs
-vm
C:\Program Files\Java\jdk-9\bin\javaw.exe
-vmargs
-Dosgi.requiredJavaVersion=1.8
--add-modules=ALL-SYSTEM