Eclipse 2025-06: UI rendering issues on Windows with monitors using different scale factors

[WinmaH]

When running Eclipse IDE for Enterprise Java and Web Developers (2025-06 release) on Windows 11, UI rendering artifacts appear on secondary monitors configured with a different scale factor (e.g., 125%). Some images/icons display with black boxes or incorrect rendering.

[Run -> Run Configuration]

Environment:

Eclipse IDE 2025-06 (tested also with Eclipse 2025-09 RC2)
Windows 11
Multi-monitor setup with different scale factors (e.g., primary monitor 100%, secondary monitor 125%)

Steps to Reproduce:

Launch Eclipse 2025-06 on Windows 11.
Use a dual-monitor setup where one monitor is set to 100% scaling and another is set to 125%.
Open the IDE on the secondary monitor (with 125% scaling).
Observe UI elements and icons.

Expected Behavior:
Icons and images should render normally, without artifacts, regardless of monitor scale factor.

Actual Behavior:
Some images/icons display with black boxes or rendering glitches on the monitor with a non-100% scale factor.

Additional Notes:

Issue is reproduced only in Windows OS
Issue occurs even when “Monitor-specific UI Scaling” is enabled in Eclipse Preferences.
Tried Windows compatibility settings → Override high DPI scaling behavior → System (Enhanced), but the issue persists.
Issue is not reproduced when both monitors use 100% scaling.
Verified with latest Eclipse 2025-09 RC2; the issue still exists.

[HeikoKlare]

I have tried to reproduce the behavior with the 2025-06 release of the package for Enterprise Java and Web Developers. I use primary monitor at 100% and secondary monitor at 125%. I have started the application from both primary and secondary monitor and opened the Run Configurations dialog on the 125% monitor or moved it there. In all cases the icon backgrounds look correct for me:

Can you give information about the JRE you are using to run Eclipse? In my case, it's Temurin 21.0.6.7. Maybe you can also try to start Eclipse with a different JRE build or version.

Tried Windows compatibility settings → Override high DPI scaling behavior → System (Enhanced), but the issue persists.

Settings DPI awareness for the process will not have any (relevant) effect as when "monitor-specific UI scaling" is enabled the application overwrites proper DPI awareness for the UI thread.

[WinmaH]

@HeikoKlare thanks for getting back to me.

I first tried with inbuilt JRE to launch Eclipse (OpenJDK21). Now tried with Temurin21 and still the issue persist.

I will re-write the exact steps with screenshots for better clarity

Screen 1

Screen 2

Launch eclipse in 125% screen [screen1]
Open Run -> Run Configuration Window
Observe no UI issues

Drag and Drop the Run Configuration Window to 100% screen [screen2]
Observe no UI issues

Drag and Drop the Run Configuration Window again to 125% screen [screen1]
Observe UI issues

I have tried with few other Windows machines and observation is the same.
Appreciate your support to resolve this issue.

[merks]

I have observed this in the past, but I changed the JDK I was using and did updates and it seemed to go away. But today I see it in my SimRel IDE in by 125% monitor:

But it's this version:

Configured with:

C:/Program Files/Java/jdk-21.0.2+13/bin

That JDK I had configured like this because in the past that worked reasonably well:

Just now I changed the eclipse.ini to

C:\Program Files\Java\jdk-21.0.8+9\bin

And now it works fine:

So at least for me the problem depends on the settings on the java.exe/javaw.exe of the JDK/JRE that that runs the IDE.

[WinmaH]

Thanks @merks for your comments

Investigated further and found that for me the issue exists regardless of the JRE used to launch Eclipse.
When the “Use Monitor-Specific UI Scaling” option (which is enabled by default starting with Eclipse 2025-06) is disabled, the above UI issue is not re-created

Release note with new feature : Eclipse 2025-06 Release Note – Monitor-specific UI scaling as default (Windows only)

[HeikoKlare]

Thank you for the detailled explanation. I was now able to reproduce the issue. It's somehow not deterministic but it happened to me in at least 50% of the executions of the described flow. Here is exactly what I did (conforms to the description ot @WinmaH):

• Have two monitors, 125% secondary to the left and 100% primary to the right
• Start an Eclipse IDE for Java and Web Developers (e.g. 2025-06 or 2025-09 RC1) from the secondary monitor; this means you can, e.g., navigate to the eclipse.exe in a Windows explorer that is placed on the secondary monitor
• Start the "Run Configurations" dialog, move it to the primary monitor and move it back to the secondary monitor:

[WinmaH]

Thanks @HeikoKlare for getting back.
As per my last comment if we disable the monitor specific ui scaling option in the preferences the issue disappears.

[HeikoKlare]

As per my last comment if we disable the monitor specific ui scaling option in the preferences the issue disappears.

Yes, that's kind of expected. Without monitor-specific scaling the UI does not scale at all, so images will also not be rescaled.

[merks]

For what it's worth, one might skip scaling on a 125% monitor and get by, but skipping it for a 200% monitor would quickly require a trip to the optimist. 👓 🔍 This is why in the past I configured JRE the way that I did. The current behavior is really quite nice other than these weird gif transparency problem...

[HeikoKlare]

Moving this issue to SWT as the cause is very likely somwhere in the scaling of images.

[ShahzaibIbrahim]

I am able to reproduce the issue with simple gif image with this concrete snippet: (Primary: 100, Secondary: 125). Background is lost when moving to 100 -> 125 and back.

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;


public class ButtonWithGifImage {
    public static void main(String[] args) {
    	System.setProperty("swt.autoScale.updateOnRuntime", "true");
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("SWT Button with GIF Image");
        shell.setSize(300, 200);

        Button button = new Button(shell, SWT.PUSH);
        button.setBounds(80, 60, 140, 60);
        button.setText("Click Me");

        Image image = new Image(display,
            ButtonWithGifImage.class.getResourceAsStream("sample.gif"));
        button.setImage(image);

        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }

        image.dispose();
        display.dispose();
    }
}

After moving back and forth, the result: