WindowBuilder crashes on opening when using custom components

[aabrami]

I deleted the eclipse folder that contained Eclipse IDE for Java Developers 2025-03.
I downloaded ZIP file for Eclipse IDE for Java Developers 2025-06 and extracted the files to the same location as the previous version.
I then downloaded the latest WindowBuilder ZIP file and installed WindowBuilder (1.20) via menu Help > Install New Software

I open an existing class with WindowBuilder Editor

I click on Design tab and a progress dialog window appears and after about one second Eclipse crashes. The whole IDE window simply disappears from the computer screen as if Eclipse was never opened. This only occurs if my GUI contains custom components, i.e. classes that extend Swing components. For example I have a class QtLabel that extends JLabel.
Needless to say, WindowBuilder (1.19) worked with Eclipse 2025-03.
Here is a relevant section from the [Eclipse] workspace log file.

!ENTRY org.eclipse.oomph.setup.core 2 0 2025-06-17 11:42:58.083
!MESSAGE C:\Users\d261506\.eclipse\org.eclipse.oomph.setup\cache\https___www.eclipse.org_setups_setups.zip (The system cannot find the path specified)
!STACK 0
java.io.FileNotFoundException: C:\Users\d261506\.eclipse\org.eclipse.oomph.setup\cache\https___www.eclipse.org_setups_setups.zip (The system cannot find the path specified)
	at java.base/java.io.FileInputStream.open0(Native Method)
	at java.base/java.io.FileInputStream.open(FileInputStream.java:213)
	at java.base/java.io.FileInputStream.<init>(FileInputStream.java:152)
	at org.eclipse.emf.ecore.resource.impl.FileURIHandlerImpl.createInputStream(FileURIHandlerImpl.java:99)
	at org.eclipse.oomph.setup.internal.core.util.SetupCoreUtil$4.createInputStream(SetupCoreUtil.java:512)
	at org.eclipse.emf.ecore.resource.impl.ExtensibleURIConverterImpl.createInputStream(ExtensibleURIConverterImpl.java:358)
	at org.eclipse.oomph.setup.internal.core.util.ECFURIHandlerImpl$InputStreamConnectionHandler.handleCache(ECFURIHandlerImpl.java:1820)
	at org.eclipse.oomph.setup.internal.core.util.ECFURIHandlerImpl$InputStreamConnectionHandler.handleCache(ECFURIHandlerImpl.java:1)
	at org.eclipse.oomph.setup.internal.core.util.ECFURIHandlerImpl$ConnectionHandler.process(ECFURIHandlerImpl.java:1755)
	at org.eclipse.oomph.setup.internal.core.util.ECFURIHandlerImpl.createInputStream(ECFURIHandlerImpl.java:320)
	at org.eclipse.emf.ecore.resource.impl.ExtensibleURIConverterImpl.createInputStream(ExtensibleURIConverterImpl.java:358)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.load(ResourceImpl.java:1314)
	at org.eclipse.oomph.setup.internal.core.util.SetupCoreUtil.handleArchiveRedirection(SetupCoreUtil.java:696)
	at org.eclipse.oomph.setup.internal.core.util.SetupCoreUtil.configureResourceSet(SetupCoreUtil.java:474)
	at org.eclipse.oomph.setup.internal.core.util.SetupCoreUtil.configureResourceSet(SetupCoreUtil.java:268)
	at org.eclipse.oomph.setup.internal.core.util.SetupCoreUtil.createResourceSet(SetupCoreUtil.java:262)
	at org.eclipse.oomph.setup.ui.recorder.RecorderManager.<clinit>(RecorderManager.java:114)
	at org.eclipse.oomph.setup.ui.SetupUIPlugin.performStartup(SetupUIPlugin.java:229)
	at org.eclipse.oomph.setup.ui.EarlyStartup.earlyStartup(EarlyStartup.java:23)
	at org.eclipse.oomph.internal.ui.EarlyStart.run(EarlyStart.java:119)
	at org.eclipse.oomph.internal.ui.EarlyStart$1.run(EarlyStart.java:98)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

[ptziegler]

The whole IDE crashing sounds like an issue somewhere in the native layer. For Swing, this either means SWT or some external component.

If this is a crash, there should be a crash log (e.g. hs_err_pid8053.log) in your Eclipse installation folder. Can you upload that? This should contain the part of the code that's causing the problem.

[aabrami]

I downloaded all the milestone build ZIP files. I got them into our company network via JFrog. I deleted the eclipse folder and reinstalled Eclipse IDE by extracting files from eclipse-java-2025-06-R-win32-x86_64.zip. Then I installed one of the milestone builds via Help > Install New Software. Then I opened a class in WindowBuilder editor. I started with the oldest milestone build, i.e. WindowBuilder-Updates-S202504090405.zip and progressed to the newest, repeating the entire process each time. The first milestone build that crashed Eclipse was S202005281712. Note that I did not [yet] try the latest milestone build, i.e. S202506031901.

[ptziegler]

If the issue happens with the S202005281712, but not the S202505210414, then the cause can be reduced to one of the following commits:

7b62981
4a70d9b
134c11e
66ef171
c55996f
87765b2
934b8f6
6065508
5d10c4a
b0bf849
f69b7dd
5a6f1eb

Excluding the ones that have no impact on the editor leaves:

7b62981
c55996f
6065508
b0bf849

which only convert some of the icons to SVGs and

87765b2
934b8f6
5d10c4a
f69b7dd

with actual code changes.

Though none of these commits give any indication of why the problem is happening... Given that the issue doesn't seem to happen with the default component, but only a custom component, I'd say the most likely candidate is 5d10c4a.

Perhaps the timing when the component is different when using double-buffering? But as I said before: Without any way to reproduce the problem, there is very little I can do to fix it. So all of this is just pure speculation...

Is there any way you can set up the WindowBuilder development environment locally and isolate which one of those commits is responsible? Otherwise it is very unlikely I or anyone else will be able to sort this one out.

[aabrami]

I don't know if this means anything to you, but now all of the milestone builds are crashing Eclipse including the ones that previously did not. In any case, I will try to provide you with a way to reproduce the crash. Again, thank you for all your help so far.

[aabrami]

I tried to create a minimal workspace that reproduces the problem, but there are so many dependencies between the various classes that the amount of code required is simply way too much. Perhaps if you can guide me as to which parts of a class that extends JLabel are relevant to WindowBuilder editor, I may be able to make a stripped down version of QtLabel that does reproduce the crash and with only a small amount of code.

[ptziegler]

I don't know if this means anything to you, but now all of the milestone builds are crashing Eclipse including the ones that previously did not.

If previously working versions start crashing all of a sudden, then I assume something else must've changed, right?

Perhaps if you can guide me as to which parts of a class that extends JLabel are relevant to WindowBuilder editor.

That solely depends on how the class is integrated. If you define your own components, I would expect a QtLabel.wbp-component.xml in whatever plugin contributes the QtLabel, which tells WindowBuilder how to work with this class. But generally, the entry point is the constructor.

But maybe to isolate the problem: You mentioned that crash itself because WindowBuilder fails to load a properties file.

Perhaps this can be simplified into a reproducer? How is this properties file loaded? e.g.

public class MyFrame extends JFrame {
    public MyFrame() {
        QtLabel.init("localappsettings.properties");
        add(new QtLabel());
    }
}

or via a different mechanism?

[ptziegler]

Also regarding the File class: Keep in mind that relative paths like new File("localappsettings.properties") will be relative wrt. to the current Java process.

When you launch the application from the project, it will be relative to that. But for the editor, the path is relative to the Eclipse installation folder.

[aabrami]

I am aware of that, but thanks anyway. I copied the properties file to the Eclipse installation folder after installing WindowBuilder and before opening a class in the WindowBuilder editor.