Since Vaadin 25 the `overlayClass` property and the `setOverlayClassName` method in Flow are gone. See: https://github.com/jmix-framework/jmix/issues/4865#issuecomment-3691362006
Since Vaadin 25 the
overlayClassproperty and thesetOverlayClassNamemethod in Flow are gone. See: jmix-framework/jmix#4865 (comment)