This bug was originally marked as duplicate of bug 218799, that is already resolved. This bug is still valid, so this seems to be another bug, but it might be related.
Build: NetBeans IDE 7.4 (Build 201310111528)
VM: Java HotSpot(TM) Client VM, 24.45-b08, Java(TM) SE Runtime Environment, 1.7.0_45-b18
OS: Windows XP
batousai99: I was creating a NEW JavaFX Main Class from the project explorer window.. While editing, I Pressed CTRL+<SPACE> to show hints.... then it suddenly stopped responding for about 3-5 minutes....
Maximum slowness yet reported was 331184 ms, average is 331184
Created attachment 141285 [details]
This old bug may not be relevant anymore. If you can still reproduce it in 8.2 development builds please reopen this issue.
Thanks for your cooperation,
NetBeans IDE 8.2 Release Boss