Comparison method violates its general contract!

[dansarie]

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Comparison method violates its general contract!
        at java.base/java.util.ComparableTimSort.mergeHi(ComparableTimSort.java:870)
        at java.base/java.util.ComparableTimSort.mergeAt(ComparableTimSort.java:487)
        at java.base/java.util.ComparableTimSort.mergeCollapse(ComparableTimSort.java:413)
        at java.base/java.util.ComparableTimSort.sort(ComparableTimSort.java:213)
        at java.base/java.util.Arrays.sort(Arrays.java:1249)
        at java.desktop/javax.swing.DefaultRowSorter.sort(DefaultRowSorter.java:616)
        at java.desktop/javax.swing.DefaultRowSorter.allRowsChanged(DefaultRowSorter.java:863)
        at java.desktop/javax.swing.JTable.notifySorter(JTable.java:4263)
        at java.desktop/javax.swing.JTable.sortedTableChanged(JTable.java:4123)
        at java.desktop/javax.swing.JTable.tableChanged(JTable.java:4400)
        at java.desktop/javax.swing.table.AbstractTableModel.fireTableChanged(AbstractTableModel.java:297)
        at java.desktop/javax.swing.table.AbstractTableModel.fireTableDataChanged(AbstractTableModel.java:199)
        at se.dansarie.jsnowball.JSnowball$SnowballTableModel.contentsChanged(JSnowball.java:1017)
        at se.dansarie.jsnowball.model.SnowballListModel.fireChanged(SnowballListModel.java:51)
        at se.dansarie.jsnowball.model.SnowballState.lambda$0(SnowballState.java:115)
        at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
        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.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
        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)
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Comparison method violates its general contract!
        at java.base/java.util.ComparableTimSort.mergeHi(ComparableTimSort.java:870)
        at java.base/java.util.ComparableTimSort.mergeAt(ComparableTimSort.java:487)
        at java.base/java.util.ComparableTimSort.mergeForceCollapse(ComparableTimSort.java:426)
        at java.base/java.util.ComparableTimSort.sort(ComparableTimSort.java:222)
        at java.base/java.util.Arrays.sort(Arrays.java:1249)
        at java.desktop/javax.swing.DefaultRowSorter.sort(DefaultRowSorter.java:616)
        at java.desktop/javax.swing.DefaultRowSorter.allRowsChanged(DefaultRowSorter.java:863)
        at java.desktop/javax.swing.JTable.notifySorter(JTable.java:4263)
        at java.desktop/javax.swing.JTable.sortedTableChanged(JTable.java:4123)
        at java.desktop/javax.swing.JTable.tableChanged(JTable.java:4400)
        at java.desktop/javax.swing.table.AbstractTableModel.fireTableChanged(AbstractTableModel.java:297)
        at java.desktop/javax.swing.table.AbstractTableModel.fireTableDataChanged(AbstractTableModel.java:199)
        at se.dansarie.jsnowball.JSnowball$SnowballTableModel.contentsChanged(JSnowball.java:1017)
        at se.dansarie.jsnowball.model.SnowballListModel.fireChanged(SnowballListModel.java:51)
        at se.dansarie.jsnowball.model.SnowballState.lambda$0(SnowballState.java:115)
        at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
        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.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
        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)