This bug was originally marked as duplicate of bug 254649, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE Dev (Build 201510201015)
VM: Java HotSpot(TM) 64-Bit Server VM, 25.66-b17, Java(TM) SE Runtime Environment, 1.8.0_66-b17
OS: Windows 8.1
GUEST: I don't know
Maximum slowness yet reported was 3897 ms, average is 3897
Created attachment 156874 [details]