This Bugzilla instance is a read-only archive of historic NetBeans bug reports. To report a bug in NetBeans please follow the project's instructions for reporting issues.
Sometimes it happens to me that gc-roots action is so fast that it apparently finishes before the progress dialog is even displayed. In such case, the dialog is displayed later and stays up forever. Note that the IDE is still usable, if you move the dialog aside.
fixed in trunk. using CountDownLatch to make sure the progress dialog is closed only after it has been opened