A number of users have reported issues with EDT. Collected here:

Access is allowed from Event Dispatch Thread (EDT) only
#344
#368
#469
#492
#524
#556
#563
#584
#622
#676

EventQueue.isDispatchThread()=false
#465
#467
#572

ActionUpdateThread.OLD_EDT is deprecated and going to be removed soon
#441
#498
#499
#539
#575
#641
#660
#670
#672
#673
#767
#768
#769
#782
#810
#824
#825
#826
#827
#828
#829
#830
#831
#832
#833
#861
#869

xx ms to call on EDT CodyStatusBarActionGroup
#631
#665
#878
#913