Getting java.lang.IllegalStateException: This must happen in the event thread!, when disabling an action

I am trying to disable an action outside actionPerformed(ActionEvent e) by using action.setEnabled(false), but I get the following error:


Code:
java.lang.IllegalStateException: This must happen in the event thread!
    at org.openide.awt.Actions$Bridge.propertyChange(Actions.java:929)
    at org.openide.util.WeakListenerImpl$PropertyChange.propertyChange(WeakListenerImpl.java:197)
    at java.beans.PropertyChangeSupport.fire(PropertyChangeSupport.java:335)
    at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:327)
    at javax.swing.event.SwingPropertyChangeSupport.firePropertyChange(SwingPropertyChangeSupport.java:92)
    at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:263)
    at javax.swing.AbstractAction.firePropertyChange(AbstractAction.java:276)
    at javax.swing.AbstractAction.setEnabled(AbstractAction.java:236)



Any ideas what I am getting this error?