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.
I accidentally invoked plugin manager from Tools -> Plugins and then immediately clicked 'Close'. The IDE deadlocked. I'm attaching the thread dump. On subsequent try all was working fine. I should mention that I 'ant testuserdir-delete'-ed my userdir before the first try.
Created attachment 55306 [details] thread dump showing the deadlock
Fixed http://hg.netbeans.org/main/rev/c8b75f040338