# Ignition 7.9: OPC Tag Tree Browser - Error Loading Children - NullPointerException

**URL:** <https://forum.inductiveautomation.com/t/ignition-7-9-opc-tag-tree-browser-error-loading-children-nullpointerexception/41483>\
**Category:** Ignition\
**Created:** [December 13, 2020, 11:41pm UTC](https://forum.inductiveautomation.com/t/ignition-7-9-opc-tag-tree-browser-error-loading-children-nullpointerexception/41483 "2020-12-13T23:41:48Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![mark.benedicto](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mark.benedicto/32/27346_2.png) [@mark.benedicto](https://forum.inductiveautomation.com/u/mark.benedicto)\
**Post date:** [December 13, 2020, 11:41pm UTC](https://forum.inductiveautomation.com/t/ignition-7-9-opc-tag-tree-browser-error-loading-children-nullpointerexception/41483/1 "2020-12-13T23:41:49Z")

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Hi all,

I just need some help in regards to the Tag Tree Browser. There are instances where I close the pop-up with this component, then Ignition gives me the error below. What is the best way to catch this? In my understanding this happens when the tag tree browser is in the middle of refreshing its contents and the closing action of the window are done simultaneously.

> java.lang.NullPointerException  
> at com.inductiveautomation.factorypmi.application.components.tagbrowsetree.TagBrowseTreeNode$TagBrowseProviderNode$FilterableTagTreeNode.loadChildren(TagBrowseTreeNode.java:360)  
> at com.inductiveautomation.ignition.client.sqltags.tree.TagTreeNode.checkChildren(TagTreeNode.java:206)  
> at com.inductiveautomation.ignition.client.sqltags.tree.AbstractTagPathTreeNode.isLeaf(AbstractTagPathTreeNode.java:349)  
> at com.inductiveautomation.ignition.client.sqltags.tree.TagTreeNode.isLeaf(TagTreeNode.java:237)  
> at com.inductiveautomation.factorypmi.application.components.tagbrowsetree.TagBrowseTreeNode$TagBrowseProviderNode.getFilteredTags(TagBrowseTreeNode.java:264)  
> at com.inductiveautomation.factorypmi.application.components.tagbrowsetree.TagBrowseTreeNode$TagBrowseProviderNode.loadChildren(TagBrowseTreeNode.java:241)  
> at com.inductiveautomation.ignition.client.sqltags.tree.AbstractTagPathTreeNode$Loader.doRun(AbstractTagPathTreeNode.java:88)  
> at com.inductiveautomation.ignition.client.sqltags.tree.AbstractTagPathTreeNode$Loader.run(AbstractTagPathTreeNode.java:129)  
> at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)  
> at java.util.concurrent.FutureTask.run(Unknown Source)  
> at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)  
> at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)  
> at java.lang.Thread.run(Unknown Source)
> 
> Ignition v7.9.11 (b2019060313)  
> Java: Oracle Corporation 1.8.0\_271

Thanks in advance.