For working with Scala in Windows 10 I use Scala IDE build on Eclipse SDK. Build-id is 4.7.1.

I have installed Java 9 and when I wanted to run Scala IDE I got an error message saying I should check the log file C:\marko\workspace\.metadata\.log.
The error message was

!ENTRY org.eclipse.osgi 4 0 2018-01-27 18:28:41.327
!MESSAGE Application error
!STACK 1
org.eclipse.e4.core.di.InjectionException: java.lang.NoClassDefFoundError: javax/annotation/PostConstruct
	at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:410)
	at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:318)
	at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:162)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.createDefaultHeadlessContext(E4Application.java:491)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.createDefaultContext(E4Application.java:505)
	at org.eclipse.e4.ui.internal.workbench.swt.E4Application.createE4Workbench(E4Application.java:204)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:614)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:594)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:151)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1499)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1472)
Caused by: java.lang.NoClassDefFoundError: javax/annotation/PostConstruct
	at org.eclipse.e4.core.internal.di.InjectorImpl.inject(InjectorImpl.java:124)
	at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:399)
	... 23 more
Caused by: java.lang.ClassNotFoundException: javax.annotation.PostConstruct cannot be found by org.eclipse.e4.core.di_1.6.100.v20170421-1418
	at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:433)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:395)
	at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:387)
	at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:150)
	at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
	... 25 more

After some googling I found out I have to make some changes to the eclipse.ini file. The following snippet shows my eclipse.ini file with changes. Scala IDE start now the way it should.

--launcher.appendVmargs
-vm
C:\Program Files\Java\jdk-9.0.1\bin\javaw.exe
-startup
plugins/org.eclipse.equinox.launcher_1.4.0.v20161219-1356.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.500.v20170531-1133
-vmargs
-Xmx2G
-Xms200m
-XX:MaxPermSize=384m
-Dosgi.requiredJavaVersion=1.8
--add-modules=ALL-SYSTEM

Highlighted code was added so that Scala IDE could work on Java 9.