# ERROR NullPointerException

**URL:** <https://forum.inductiveautomation.com/t/error-nullpointerexception/15489>\
**Category:** General Discussion\
**Created:** [September 28, 2017, 2:19am UTC](https://forum.inductiveautomation.com/t/error-nullpointerexception/15489 "2017-09-28T02:19:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![antoniosantos\_ccb](https://avatars.discourse-cdn.com/v4/letter/a/e0b2c6/32.png) [@antoniosantos\_ccb](https://forum.inductiveautomation.com/u/antoniosantos_ccb)\
**Post date:** [September 28, 2017, 2:19am UTC](https://forum.inductiveautomation.com/t/error-nullpointerexception/15489/1 "2017-09-28T02:19:00Z")

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I have this problem:

Traceback (most recent call last):

File “event:actionPerformed”, line 4, in

java.lang.NullPointerException: java.lang.NullPointerException

```
caused by NullPointerException

```

Ignition v7.9.4 (b2017082911)  
Java: Oracle Corporation 1.8.0\_144

MY CODE IS:  
windowsOpened = system.gui.getOpenedWindows()  
if ‘Dettaglio Azione’ in str(windowsOpened):  
#window = system.gui.getWindow(‘Database/Anagrafica Ricette/Dettaglio Azione’)  
system.nav.closeWindow(‘Database/Anagrafica Ricette/Dettaglio Azione’) # chiude finestra  
event.source.path = “Builtin/icons/16/navigate\_left.png” # cammbia icona pulsante  
#project.Global.inserisciInFinestreDokedOpend( ‘Database/Anagrafica Ricette/Cerca Ricetta’, ‘’) #toglie da code wodked windows aperte   
else:  
system.nav.openWindow(“Database/Anagrafica Ricette/Dettaglio Azione”) #apre finestra  
event.source.path = “Builtin/icons/16/navigate\_right.png” # cammbia icona pulsante

 ![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/4/47e642ad7bfb3b1d3b9502a98c6655754f853376.PNG)

AND THEN I TRY TO EXECUTE AGAIN AND SEE THE IMAGE!

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<div class="post-metadata">

**Author:** ![antoniosantos\_ccb](https://avatars.discourse-cdn.com/v4/letter/a/e0b2c6/32.png) [@antoniosantos\_ccb](https://forum.inductiveautomation.com/u/antoniosantos_ccb)\
**Post date:** [September 28, 2017, 1:35pm UTC](https://forum.inductiveautomation.com/t/error-nullpointerexception/15489/2 "2017-09-28T13:35:47Z")

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I get it. The error was mine, but in other code.