Linear gradient causes "class javafx.scene.paint.LinearGradient cannot be cast to class javafx.scene.paint.Color"

[DBChoco]

Describe the bug
When using this
-common-gradient: linear-gradient(to right bottom, #0af6bb, #420aa4);
with this

.mfx-checkbox, .mfx-radio-button{
    -mfx-main: -common-gradient;
}

I get this:

May 17, 2022 12:24:03 AM javafx.scene.CssStyleHelper calculateValue
WARNING: Caught 'java.lang.ClassCastException: class javafx.scene.paint.LinearGradient cannot be cast to class javafx.scene.paint.Color (javafx.scene.paint.LinearGradient and javafx.scene.paint.Color are in module javafx.graphics@18-ea of loader 'app')' while converting value for '-mfx-ripple-color' from rule '*.mfx-checkbox *.ripple-container *.mfx-ripple-generator' in stylesheet jar:file:///home/XXXXXX/.m2/repository/io/github/palexdev/materialfx/11.13.5/materialfx-11.13.5.jar!/io/github/palexdev/materialfx/css/MFXCheckBox.css

MRE(Minimal Reproducible Example)
Project is here

To Reproduce
Steps to reproduce the behavior:

1. Just run the Main, then go to the "Settings" scene, where all the checkboxes are.

Screenshots
The css does work, it just shows a lot of error messages

[palexdev]

I'll check this asap

[palexdev]

@DBChoco found the issue
Both MFXCheckbox and MFXRadioButton have something like this -mfx-ripple-color: derive(-mfx-main, percentage); to make the ripple color depend on the main color
The CSS derive(...) function however cannot operate on gradients, so if you don't override that rule too you'll see the errors and the ripple color will fallback to gray