SWT getMenu() NPE

[stas-bob]

In my eclipse 2025-03 PDE on windows, when starting an eclipse product from my launch config and having set the preference for dark mode, eclipse will not start and crash with this exception:

Suppressed: java.lang.NullPointerException: Cannot invoke "org.eclipse.swt.widgets.Menu.getShell()" because the return value of "org.eclipse.swt.widgets.MenuItem.getMenu()" is null
	at org.eclipse.swt.widgets.MenuItem.getMonitorZoom(MenuItem.java:1131)
	at org.eclipse.swt.widgets.MenuItem.createNewGC(MenuItem.java:1125)
	at org.eclipse.swt.widgets.MenuItem.wmDrawChild(MenuItem.java:1148)
	at org.eclipse.swt.widgets.Control.WM_DRAWITEM(Control.java:4979)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:4771)
	... 42 more
Suppressed: java.lang.NullPointerException: Cannot invoke "org.eclipse.swt.widgets.Menu.getShell()" because the return value of "org.eclipse.swt.widgets.MenuItem.getMenu()" is null
	at org.eclipse.swt.widgets.MenuItem.getMonitorZoom(MenuItem.java:1131)
	at org.eclipse.swt.widgets.MenuItem.createNewGC(MenuItem.java:1125)
	at org.eclipse.swt.widgets.MenuItem.wmDrawChild(MenuItem.java:1148)
	at org.eclipse.swt.widgets.Control.WM_DRAWITEM(Control.java:4979)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:4771)
	... 42 more

Eclipse starts fine again, when i remove the dark mode preference (org.eclipse.e4.ui.css.theme.e4_dark)

But this dark mode preference used to work in eclipse earlier versions.

My .launch config:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<launchConfiguration type="org.eclipse.pde.ui.RuntimeWorkbench">
    <booleanAttribute key="append.args" value="true"/>
    <booleanAttribute key="askclear" value="true"/>
    <booleanAttribute key="automaticAdd" value="true"/>
    <booleanAttribute key="automaticValidate" value="false"/>
    <stringAttribute key="bootstrap" value=""/>
    <stringAttribute key="checked" value="[NONE]"/>
    <booleanAttribute key="clearConfig" value="true"/>
    <booleanAttribute key="clearws" value="false"/>
    <booleanAttribute key="clearwslog" value="false"/>
    <stringAttribute key="configLocation" value="${workspace_loc}/.metadata/.plugins/org.eclipse.pde.core/RunEclipse"/>
    <booleanAttribute key="default" value="true"/>
    <booleanAttribute key="includeOptional" value="true"/>
    <stringAttribute key="location" value="${workspace_loc}/../runtime-EclipseXtext"/>
    <booleanAttribute key="org.eclipse.debug.core.ATTR_FORCE_SYSTEM_CONSOLE_ENCODING" value="false"/>
    <stringAttribute key="org.eclipse.debug.core.source_locator_id" value="org.eclipse.pde.ui.launcher.PDESourceLookupDirector"/>
    <listAttribute key="org.eclipse.debug.ui.favoriteGroups">
        <listEntry value="org.eclipse.debug.ui.launchGroup.debug"/>
        <listEntry value="org.eclipse.debug.ui.launchGroup.run"/>
    </listAttribute>
    <booleanAttribute key="org.eclipse.jdt.launching.ATTR_ATTR_USE_ARGFILE" value="false"/>
    <booleanAttribute key="org.eclipse.jdt.launching.ATTR_SHOW_CODEDETAILS_IN_EXCEPTION_MESSAGES" value="true"/>
    <stringAttribute key="org.eclipse.jdt.launching.JRE_CONTAINER" value="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-21"/>
    <stringAttribute key="org.eclipse.jdt.launching.PROGRAM_ARGUMENTS" value="-os ${target.os} -ws ${target.ws} -arch ${target.arch} -nl ${target.nl} -clean"/>
    <stringAttribute key="org.eclipse.jdt.launching.SOURCE_PATH_PROVIDER" value="org.eclipse.pde.ui.workbenchClasspathProvider"/>
    <stringAttribute key="org.eclipse.jdt.launching.VM_ARGUMENTS" value="-Xmx8g -Ddev-mode=true"/>
    <stringAttribute key="pde.version" value="3.3"/>
    <stringAttribute key="product" value="org.eclipse.platform.ide"/>
    <booleanAttribute key="show_selected_only" value="false"/>
    <stringAttribute key="templateConfig" value="${target_home}/configuration/config.ini"/>
    <booleanAttribute key="tracing" value="false"/>
    <booleanAttribute key="useCustomFeatures" value="false"/>
    <booleanAttribute key="useDefaultConfig" value="true"/>
    <booleanAttribute key="useDefaultConfigArea" value="true"/>
    <booleanAttribute key="useProduct" value="true"/>
    <booleanAttribute key="usefeatures" value="false"/>
</launchConfiguration>

[fedejeanne]

It seems this one slipped through the cracks, @ShahzaibIbrahim . It was introduced by #1405, we missed this tiny detail:

Can you please look into it?

[fedejeanne]

FTR @ShahzaibIbrahim , it seems Mac had a similar issue about the application menu bar: bf0af7a

[fedejeanne]

I am trying to reproduce this in the latest I-BUILD and I can't. @stas-bob can you please provide the precise steps you followed in order to reproduce this error?

[stas-bob]

Please use my launch config to start an eclipse product. In that eclipse change appearance to dark mode. Close eclipse and try to restart. For me it now crashes with the NPE

[fedejeanne]

I tried that and I can't see the error. I'm using the latest master.

Are you able to reproduce it in the latest I-BUILD (or at least in 2025-06) too?

[stas-bob]

I still get that problem in my eclipse 2025-06. Also from your screenshot, you show documentation of getShell(). The null is returned by getMenu()

[fedejeanne]

I still get that problem in my eclipse 2025-06

Hm, tricky. Without being able to reproduce the error, it is difficult to validate any possible solution. Can you please describe the exact steps you followed in order to reproduce this error?

Here's what I did:

• Go to plugin org.eclipse.e4.ui.workbench
• Create a file called my.launch and paste the content you provided.
• Right click on my.launch -> Run As \ 1 my (the application starts)
• Go to Window \ Preferences and change to dark mode
• Restart
• Application is restarted and is using the dark mode. No NPEs in the console or in the Error Log view

[stas-bob]

At which point should setMenu() be called on menuItem? It is not called, so menu remains null...

[stas-bob]

ok i tracked down to the file .metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi

If i remove that file, eclipse starts correctly with dark mode.

[stas-bob]

When i restart again, it again crashes with that NPE. I always have to remove the workbench.xmi file for a start. Sorry i cant provide better steps because im really not doing anything else other than restarting eclipse after setting dark mode.

[stas-bob]

Ok I found the issue. It is a problem in my workspace. One of the loaded plugins define this:

 <extension
     point="org.eclipse.ui.menus">
       <menuContribution
            locationURI="menu:org.eclipse.ui.main.menu?after=additions">
            <command
                commandId="org.eclipse.ui.window.preferences"
                label="Preferences"
                style="push">
          </command>
          <command
                  commandId="org.eclipse.ui.help.aboutAction"
                  label="About"
                  icon="icons/empty.png"
                  style="push"> 
            </command>
       </menuContribution>
   </extension>

This plugin project is open by mistake. It is pointless to load this plugin for the normal eclipse product, since these menus exist already. Apparently this menu contribution (which is redundant/a duplicate for eclipse product) causes an issue for dark mode. For light mode this menu contribution will not break the start.

Thanks for supporting me

[fedejeanne]

My pleasure.

FTR I would still like to analyze this issue (or rather a very similar one) because adding the 2 contributions that you provided to org.eclipse.ui.examples.contributions also results in an exception.

To reproduce:

• Add the 2 menu contributions to org.eclipse.ui.examples.contributions
• Run the Runtime Workspace launch configuration

Stack trace:

java.lang.NullPointerException: Cannot invoke "org.eclipse.swt.widgets.Menu.getShell()" because the return value of "org.eclipse.swt.widgets.MenuItem.getMenu()" is null
	at org.eclipse.swt.widgets.MenuItem.calculateRenderedTextSize(MenuItem.java:1310)
	at org.eclipse.swt.widgets.MenuItem.wmMeasureChild(MenuItem.java:1253)
	at org.eclipse.swt.widgets.Control.WM_MEASUREITEM(Control.java:5260)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:4820)
	at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:336)
	at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1494)
	at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:2378)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:5128)
	at org.eclipse.swt.internal.win32.OS.DefWindowProc(Native Method)
	at org.eclipse.swt.widgets.Shell.callWindowProc(Shell.java:504)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:4881)
	at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:336)
	at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1494)
	at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:2371)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:5128)
	at org.eclipse.swt.internal.win32.OS.BringWindowToTop(Native Method)
	at org.eclipse.swt.widgets.Decorations.bringToTop(Decorations.java:215)
	at org.eclipse.swt.widgets.Shell.open(Shell.java:1284)
	at org.eclipse.e4.ui.workbench.renderers.swt.WBWRenderer.postProcess(WBWRenderer.java:743)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:676)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:762)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:727)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:47)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:711)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1079)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1042)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:678)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:339)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:583)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:185)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:219)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:149)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:115)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:467)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:298)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:627)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1431)
	at org.eclipse.equinox.launcher.Main.main(Main.java:1403)
	Suppressed: java.lang.NullPointerException: Cannot invoke "org.eclipse.swt.widgets.Menu.getShell()" because the return value of "org.eclipse.swt.widgets.MenuItem.getMenu()" is null
		... 44 more

@ShahzaibIbrahim can you please take a look?