This issue was originally marked as duplicate of issue 172500, that is already resolved. This issue is still valid, so this seems to be another issue, but it might be related.

Build: NetBeans IDE Dev (Build 091102)
VM: Java HotSpot(TM) 64-Bit Server VM, 14.2-b01, Java(TM) SE Runtime Environment, 1.6.0_16-b01
OS: Windows 7, 6.1, amd64

User Comments:
charlweed: Clicked "SaveALL" button.

GUEST: Restarting the IDE, after a software-suggested update.

GUEST: I was opening the IDE...

charlweed: Launching

j_c_unwin: I was starting Netbeans

GUEST: I was writing code while downloading plugins

charlweed: Startup

GUEST: Just Started IDE

GUEST: Just viewing avaible updates in Plugins Window

GUEST: restarted netbeans after update

digz6666: After netbeans start

mpapis: Started netbeans ... Scanning projects was in progress, and I have started oppenind project tree (rails app)

GUEST: Restarting Netbeans after update, with Scala project open.

GUEST: starting netbeans

jungmat: at IDE startup

GUEST: Starting NetBeans with no project open.

bingalls: restarted a plugin update. Prior scanning php project did not complete

GUEST: at the time of starting netbeans

charlweed: Starting NB.

GUEST: I had just opened the IDE up and it was going through its initialisation procedures.

recjake: just popped up, directly after starting NB

GUEST: Updating (6.7.1 to 6.8 M2 thanks to 6.8 M2 update center).

GUEST: starting netbeans

jungmat: happens during IDE opening

GUEST: strating Netbeans on a Python project

GUEST: I was opening Netbeans

gsx: Just starting IDE. No actions by me.
Problem occurs Immediately after IDE is loaded.

GUEST: Just opened NetBeans

GUEST: Just restarted the IDE after an update

GUEST: Starting up Netbeans 6.7 after a plugin update

GUEST: Just starting the IDE after getting updates

charlweed: Starting

GUEST: Starting up

GUEST: Restart after update

witstart: Starting netbeans after adding the nightly build update centre

leopard2av: Start the ide after update with Latest Development Plugins

gawrik: by initialize refresh all from ScanOnDemand plugin

GUEST: starting program

GUEST: Lors de mises � jour automatiques

GUEST: I tried to run an small aplication, that I have been studying.

GUEST: First run of 6.7.1 displays an error on startup.

GUEST: I installed two available updates and restarted NB. Cannot remember what were the updates.

GUEST: Updated the plugins and this problem showed up during the restart. It looks, NetBeans came up just fine

charlweed: Opening graphical diff window on C++ source file.

j_c_unwin: I had just installed updates, restarted NetBeans and then right clicked a project in the left-hand "Files" tab.

GUEST: open plugins center

GUEST: Abrindo o Netbeans

GUEST: Boite Plugins ouverte su l'onglet Updates. clique sur l'onglet Settings.

GUEST: D�marrage apr�s mise � jour

henrik1409: I've just updated (2 updates - both related to the internal updater) - and when i startup Netbeans - this error came....

GUEST: startup



Stacktrace: 
java.lang.NullPointerException
        at javax.swing.ImageIcon.<init>(ImageIcon.java:190)
        at org.netbeans.core.ui.notifications.BalloonManager$DismissButton.<init>(BalloonManager.java:488)
        at org.netbeans.core.ui.notifications.BalloonManager$Balloon.<init>(BalloonManager.java:271)
        at org.netbeans.core.ui.notifications.BalloonManager.show(BalloonManager.java:117)
        at org.netbeans.core.ui.notifications.FlashingIcon$1.run(FlashingIcon.java:287)
        at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)