Occasionally when configuring colors: java.lang.IllegalStateException: Trying to unblock window blocked by another dialog

[UlyssesZh]

This error is reported (not-crashingly) occasionally when configuring colors:

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Trying to unblock window blocked by another dialog

This error happens sometimes when I hit the cancel or ok button of the color configuration window. The window does not close as expected if the error is triggered.

Command line output

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Trying to unblock window blocked by another dialog
	at java.desktop/sun.awt.X11.XWindowPeer.setModalBlocked(XWindowPeer.java:1630)
	at java.desktop/sun.awt.X11.XWindowPeer.setModalBlocked(XWindowPeer.java:1607)
	at java.desktop/java.awt.Window.setModalBlocked(Window.java:1529)
	at java.desktop/java.awt.Dialog.unblockWindow(Dialog.java:1561)
	at java.desktop/java.awt.Dialog.modalHide(Dialog.java:1447)
	at java.desktop/java.awt.Dialog.hideAndDisposePreHandler(Dialog.java:1122)
	at java.desktop/java.awt.Dialog.hide(Dialog.java:1151)
	at java.desktop/java.awt.Component.show(Component.java:1718)
	at java.desktop/java.awt.Component.setVisible(Component.java:1663)
	at java.desktop/java.awt.Window.setVisible(Window.java:1031)
	at java.desktop/java.awt.Dialog.setVisible(Dialog.java:1005)
	at java.desktop/javax.swing.JOptionPane$1.propertyChange(JOptionPane.java:1003)
	at java.desktop/java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:341)
	at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:333)
	at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:266)
	at java.desktop/java.awt.Component.firePropertyChange(Component.java:8731)
	at java.desktop/javax.swing.JOptionPane.setValue(JOptionPane.java:1953)
	at java.desktop/javax.swing.plaf.basic.BasicOptionPaneUI$ButtonActionListener.actionPerformed(BasicOptionPaneUI.java:1348)
	at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
	at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
	at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
	at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
	at java.desktop/javax.swing.plaf.basic.BasicButtonListener.focusLost(BasicButtonListener.java:222)
	at java.desktop/java.awt.Component.processFocusEvent(Component.java:6527)
	at java.desktop/java.awt.Component.processEvent(Component.java:6391)
	at java.desktop/java.awt.Container.processEvent(Container.java:2263)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5011)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
	at java.desktop/java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1950)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:1059)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:725)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4892)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.SentEvent.dispatch(SentEvent.java:70)
	at java.desktop/java.awt.DefaultKeyboardFocusManager$DefaultKeyboardFocusManagerSentEvent.dispatch(DefaultKeyboardFocusManager.java:248)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.sendMessage(DefaultKeyboardFocusManager.java:275)
	at java.desktop/java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:795)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4892)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
	at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.SequencedEvent.dispatch(SequencedEvent.java:202)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:117)
	at java.desktop/java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:190)
	at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:235)
	at java.desktop/java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:233)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.desktop/java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:233)
	at java.desktop/java.awt.Dialog.show(Dialog.java:1070)
	at java.desktop/java.awt.Component.show(Component.java:1716)
	at java.desktop/java.awt.Component.setVisible(Component.java:1663)
	at java.desktop/java.awt.Window.setVisible(Window.java:1031)
	at java.desktop/java.awt.Dialog.setVisible(Dialog.java:1005)
	at dev.roanh.util.Dialog.showDialog(Dialog.java:178)
	at dev.roanh.util.Dialog.showSaveDialog(Dialog.java:89)
	at dev.roanh.util.Dialog.showSaveDialog(Dialog.java:99)
	at dev.roanh.kps.ui.dialog.ColorDialog.configureColors(ColorDialog.java:118)
	at dev.roanh.kps.Menu.lambda$createMenu$18(Menu.java:251)
	at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1967)
	at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2308)
	at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
	at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
	at java.desktop/javax.swing.AbstractButton.doClick(AbstractButton.java:369)
	at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1020)
	at java.desktop/javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:1064)
	at java.desktop/java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:297)
	at java.desktop/java.awt.Component.processMouseEvent(Component.java:6635)
	at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
	at java.desktop/java.awt.Component.processEvent(Component.java:6400)
	at java.desktop/java.awt.Container.processEvent(Container.java:2263)
	at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5011)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
	at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
	at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4547)
	at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
	at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
	at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2772)
	at java.desktop/java.awt.Component.dispatchEvent(Component.java:4843)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
	at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

OS is Linux, with X11.