Bug? Warning when setting TextSize to Button in JDK17+

[aeric]

When I use JDK17/19/21 with designer script,

Button1.TextSize = 18

I get the following warning:

Jun 30, 2025 12:14:42 AM javafx.scene.CssStyleHelper calculateValue
WARNING: Caught 'java.lang.ClassCastException: class java.lang.String cannot be cast to class javafx.scene.paint.Paint (java.lang.String is in module java.base of loader 'bootstrap'; javafx.scene.paint.Paint is in module [email protected] of loader 'app')' while converting value for '-fx-background-color' from rule '*.button' in stylesheet jar:file:///C:/Java/jdk-19.0.2/bin/../javafx/lib/javafx.controls.jar!/com/sun/javafx/scene/control/skin/modena/modena.bss

There is no warning if I set TextSize to Label.
This warning also not showed in JDK11 or JDK14.

I tried with JDK24, I get the following warning message:

WARNING: A restricted method in java.lang.System has been called
WARNING: java.lang.System::load has been called by com.sun.glass.utils.NativeLibLoader in module javafx.graphics (file:/C:/Java/jdk-24.0.1/bin/../javafx/lib/javafx.graphics.jar)
WARNING: Use --enable-native-access=javafx.graphics to avoid a warning for callers in this module
WARNING: Restricted methods will be blocked in a future release unless native access is enabled
Waiting for debugger to connect...
Program started.
Jun 30, 2025 12:26:49 AM javafx.scene.CssStyleHelper calculateValue
WARNING: Caught 'java.lang.ClassCastException: class java.lang.String cannot be cast to class javafx.scene.paint.Paint (java.lang.String is in module java.base of loader 'bootstrap'; javafx.scene.paint.Paint is in module [email protected] of loader 'app')' while converting value for '-fx-background-color' from rule '*.button' in stylesheet jar:file:///C:/Java/jdk-24.0.1/bin/../javafx/lib/javafx.controls.jar!/com/sun/javafx/scene/control/skin/modena/modena.bss
WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::allocateMemory has been called by com.sun.marlin.OffHeapArray (file:/C:/Java/jdk-24.0.1/bin/../javafx/lib/javafx.graphics.jar)
WARNING: Please consider reporting this to the maintainers of class com.sun.marlin.OffHeapArray
WARNING: sun.misc.Unsafe::allocateMemory will be removed in a future release

 

[aeric]

It seems it is related to this post

Java 24 Warnings

For those following the problem I'm encountering with a legacy app, after unsuccessfully trying Java 21 to see if that improved the reliability of videos played in MediaView under Win11, I thought I'd try Java 24. While the app compiles and runs, the following warnings are being thrown...

www.b4x.com

Edit:

#VirtualMachineArgs: --enable-native-access=javafx.graphics --sun-misc-unsafe-memory-access=allow

Adding the above code only suppress the other warnings but the javafx.scene.CssStyleHelper calculateValue warning still persist.

 

[Erel]

It looks like a bug in JavaFX: https://bugs.openjdk.org/browse/JDK-8291853

Note that it also happens when setting the text size from the code.

 

[aeric]

Any recommendations?
I know it is just a warning, I can ignore it but I think I will stick to jdk14 at the moment.

 

[Erel]

JDK 19 is the recommended version for now. Ignore the warning.