# Property Change Null Pointer when Saving Designer

**URL:** <https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041>\
**Category:** Ignition\
**Tags:** ignition81, vision, scripting\
**Created:** [December 31, 2025, 9:35pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041 "2025-12-31T21:35:03Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [December 31, 2025, 9:35pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/1 "2025-12-31T21:35:03Z")

</div>

I’ve got a property change script that works well. For some reason I get a null pointer error in my script now. I’ve tried adding checks before it gets to the line that causes the issue but I’m still getting the error. Shouldn’t my if statements catch the null and just do nothing with it?

```python
if event.propertyName == 'selectedTab':
	
	selectedTab = event.source.selectedTab
	
	if selectedTab and event.source.parent.getComponent('Tier2_'+selectedTab).tabData:
		event.source.parent.getComponent('Tier2').tabData = event.source.parent.getComponent('Tier2_'+selectedTab).tabData

```

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/3/9/39c8be115857a1ad6f156b5a1a21387074a8ef9c.png)

This error never occurs during “normal runtime” but only when I save the designer - still somewhat annoying for the operators.

---

<div class="post-metadata">

**Author:** ![JordanCClark](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/jordancclark/32/83362_2.png) [@JordanCClark](https://forum.inductiveautomation.com/u/JordanCClark)\
**Post date:** [January 2, 2026, 11:48am UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/2 "2026-01-02T11:48:17Z")

</div>

If I were to guess, the _value_ for the Tier2 tabdata is going null when you save, and isn't refreshed in time for the event. The object itself is still there.

Maybe try something like:

```python
if event.propertyName == 'selectedTab':
	selectedTab = event.source.selectedTab
	tabData = event.source.parent.getComponent('Tier2_'+selectedTab).tabData
	
	if selectedTab is not None and hasattr(tabData, ' __len__'):
			event.source.parent.getComponent('Tier2').tabData = tabData

```

Personally, I've moved tab data to a document tag (or a folder of dataset tags before document tags were a thing).

---

<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [January 5, 2026, 2:27pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/3 "2026-01-05T14:27:07Z")

</div>

So you’re saying some value within the `tabData` dataset is null and causing issue when it’s being accessed by vision? That’s word because this has been working for _at least a year_ with no null pointer issue until last week.

But why is the issue with the _script_ then and not just a temporary _binding_ issue that resolves itself? The error popup specifically says the issue is with line 6. However, the error also says the issue is with the `getValueAt` function, which I am not explicitly calling.

Perhaps a try-catch would be the solution here. Try to assign it and do nothing when the error is caught. Although, we probably don’t want to catch _every_ error and just throw it out.

---

<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [January 5, 2026, 2:31pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/4 "2026-01-05T14:31:45Z")

</div>

In Vision, property assignments are **synchronous**. You are assigning a dataset to the `Tier2` component's `.tabData`. Anything that component needs to do upon assignment (including retrieving content from the dataset) will happen **within** that line of your script. So the component's use of `.getValueAt()` can show up as if it is a script error.

You should inspect your dataset content.

---

<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [January 5, 2026, 2:32pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/5 "2026-01-05T14:32:31Z")

</div>

I’ll check to see if I’ve got any null's in the dataset

---

<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [January 5, 2026, 3:48pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/6 "2026-01-05T15:48:07Z")

</div>

I believe I found the issue. All of my tab strips are 10 tabs long. This one somehow got changed to 9. Adding in the 10th strip fixed it.

---

<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [January 7, 2026, 2:21pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/7 "2026-01-07T14:21:57Z")

</div>

So, that was not my issue actually. I’ve recreated the issue in the designer now and I get a slightly different error.

```python
java.lang.Exception: Error setting property to 'Dataset [13R ⅹ 24C]' for binding on
DockedNav.Root Container.Tier2_7.tabData
	at com.inductiveautomation.factorypmi.application.binding.AbstractPropertyAdapter.updateTarget(AbstractPropertyAdapter.java:333)
	at com.inductiveautomation.factorypmi.application.binding.CellUpdateAdapter.updateTarget(CellUpdateAdapter.java:214)
	at com.inductiveautomation.factorypmi.application.binding.AbstractPropertyAdapter.updateValue(AbstractPropertyAdapter.java:271)
	at com.inductiveautomation.factorypmi.application.binding.CellUpdateAdapter.eval(CellUpdateAdapter.java:185)
	at com.inductiveautomation.factorypmi.application.binding.CellUpdateAdapter.propertyChange(CellUpdateAdapter.java:200)
	at java.desktop/java.beans.PropertyChangeSupport.fire(Unknown Source)
	at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
	at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
	at java.desktop/java.awt.Component.firePropertyChange(Unknown Source)
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.localeChanged(PMITabStrip.java:210)
	at com.inductiveautomation.vision.api.client.components.model.AbstractVisionPanel.startupComponent(AbstractVisionPanel.java:222)
	at com.inductiveautomation.factorypmi.application.components.util.ComponentVisitor$StartupVisitor.visit(ComponentVisitor.java:344)
	at com.inductiveautomation.factorypmi.application.components.util.ComponentVisitor.walk(ComponentVisitor.java:95)
	at com.inductiveautomation.factorypmi.application.components.util.ComponentVisitor.walk(ComponentVisitor.java:73)
	at com.inductiveautomation.factorypmi.application.FPMIWindow.startup(FPMIWindow.java:347)
	at com.inductiveautomation.factorypmi.designer.workspace.WindowWorkspace$DesigntimeWindowOpener.openWindow(WindowWorkspace.java:3880)
	at com.inductiveautomation.factorypmi.designer.workspace.WindowWorkspace.openWindow(WindowWorkspace.java:1528)
	at com.inductiveautomation.factorypmi.designer.model.navtree.WindowNode.open(WindowNode.java:260)
	at com.inductiveautomation.ignition.designer.navtree.model.AbstractResourceNavTreeNode.onDoubleClick(AbstractResourceNavTreeNode.java:428)
	at com.inductiveautomation.ignition.designer.navtree.NavTreePanel$MouseListener.lambda$mousePressed$1(NavTreePanel.java:722)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(Unknown Source)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.desktop/java.awt.EventQueue$4.run(Unknown Source)
	at java.desktop/java.awt.EventQueue$4.run(Unknown Source)
	at java.base/java.security.AccessController.doPrivileged(Unknown Source)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.desktop/java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.Boolean.booleanValue()" because the return value of "com.inductiveautomation.ignition.common.Dataset.getValueAt(int, int)" is null
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.tabExistsAndIsEnabled(PMITabStrip.java:454)
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.setSelectedTab(PMITabStrip.java:480)
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.setTabData(PMITabStrip.java:544)
	at jdk.internal.reflect.GeneratedMethodAccessor88.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at com.inductiveautomation.factorypmi.application.binding.AbstractPropertyAdapter.updateTarget(AbstractPropertyAdapter.java:326)
	... 32 more

Ignition v8.1.35 (b2023120517)
Java: Azul Systems, Inc. 17.0.8

```

It seems that I may have another coalesce issue where a binding is being executed with a null property before the binding on that property can be executed.

\*\*edit - That’s not it either. I have a cell update binding on the `tabData` dataset (for the Enabled column) that I was thinking was the issue, but I’ve coalesced the nulls to False and still get the error.

I now get one error for each of the bindings on this tab strip’s `tabData` .

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/c/3/c3e7ee761c710911d23db5b1121f47338ae59bcd.png)

```python
java.lang.Exception: Error setting property to 'Dataset [13R ⅹ 24C]' for binding on
DockedNav.Root Container.Tier2_7.tabData
	at com.inductiveautomation.factorypmi.application.binding.AbstractPropertyAdapter.updateTarget(AbstractPropertyAdapter.java:333)
	at com.inductiveautomation.factorypmi.application.binding.CellUpdateAdapter.updateTarget(CellUpdateAdapter.java:214)
	at com.inductiveautomation.factorypmi.application.binding.AbstractPropertyAdapter.updateValue(AbstractPropertyAdapter.java:271)
	at com.inductiveautomation.factorypmi.application.binding.CellUpdateAdapter.eval(CellUpdateAdapter.java:185)
	at com.inductiveautomation.factorypmi.application.binding.CellUpdateAdapter.propertyChange(CellUpdateAdapter.java:200)
	at java.desktop/java.beans.PropertyChangeSupport.fire(Unknown Source)
	at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
	at java.desktop/java.beans.PropertyChangeSupport.firePropertyChange(Unknown Source)
	at java.desktop/java.awt.Component.firePropertyChange(Unknown Source)
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.localeChanged(PMITabStrip.java:210)
	at com.inductiveautomation.vision.api.client.components.model.AbstractVisionPanel.startupComponent(AbstractVisionPanel.java:222)
	at com.inductiveautomation.factorypmi.application.components.util.ComponentVisitor$StartupVisitor.visit(ComponentVisitor.java:344)
	at com.inductiveautomation.factorypmi.application.components.util.ComponentVisitor.walk(ComponentVisitor.java:95)
	at com.inductiveautomation.factorypmi.application.components.util.ComponentVisitor.walk(ComponentVisitor.java:73)
	at com.inductiveautomation.factorypmi.application.FPMIWindow.startup(FPMIWindow.java:347)
	at com.inductiveautomation.factorypmi.designer.workspace.WindowWorkspace$DesigntimeWindowOpener.openWindow(WindowWorkspace.java:3880)
	at com.inductiveautomation.factorypmi.designer.workspace.WindowWorkspace.openWindow(WindowWorkspace.java:1528)
	at com.inductiveautomation.factorypmi.designer.workspace.WindowWorkspace$4.lambda$createPanels$2(WindowWorkspace.java:630)
	at com.inductiveautomation.ignition.designer.workspacewelcome.RecentlyModifiedTilePanel$Tile.lambda$new$1(RecentlyModifiedTilePanel.java:206)
	at com.inductiveautomation.ignition.client.util.gui.Listen$1.mousePressed(Listen.java:52)
	at java.desktop/java.awt.AWTEventMulticaster.mousePressed(Unknown Source)
	at java.desktop/java.awt.Component.processMouseEvent(Unknown Source)
	at java.desktop/javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.desktop/java.awt.Component.processEvent(Unknown Source)
	at java.desktop/java.awt.Container.processEvent(Unknown Source)
	at java.desktop/java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.desktop/java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.desktop/java.awt.Component.dispatchEvent(Unknown Source)
	at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.desktop/java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.desktop/java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.desktop/java.awt.Component.dispatchEvent(Unknown Source)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.desktop/java.awt.EventQueue$4.run(Unknown Source)
	at java.desktop/java.awt.EventQueue$4.run(Unknown Source)
	at java.base/java.security.AccessController.doPrivileged(Unknown Source)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.desktop/java.awt.EventQueue$5.run(Unknown Source)
	at java.desktop/java.awt.EventQueue$5.run(Unknown Source)
	at java.base/java.security.AccessController.doPrivileged(Unknown Source)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
	at java.desktop/java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.desktop/java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.Boolean.booleanValue()" because the return value of "com.inductiveautomation.ignition.common.Dataset.getValueAt(int, int)" is null
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.tabExistsAndIsEnabled(PMITabStrip.java:454)
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.setSelectedTab(PMITabStrip.java:480)
	at com.inductiveautomation.factorypmi.application.components.tabstrip.PMITabStrip.setTabData(PMITabStrip.java:544)
	at jdk.internal.reflect.GeneratedMethodAccessor88.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.base/java.lang.reflect.Method.invoke(Unknown Source)
	at com.inductiveautomation.factorypmi.application.binding.AbstractPropertyAdapter.updateTarget(AbstractPropertyAdapter.java:326)
	... 50 more

Ignition v8.1.35 (b2023120517)
Java: Azul Systems, Inc. 17.0.8

```

the dataset:

```python
"#NAMES"
"NAME","DISPLAY_NAME","ENABLED","HIDDEN","HOVER_COLOR","SELECTED_IMAGE_PATH","SELECTED_IMAGE_HORIZONTAL_ALIGNMENT","SELECTED_IMAGE_VERTICAL_ALIGNMENT","SELECTED_FOREGROUND_COLOR","SELECTED_BACKGROUND_COLOR","SELECTED_FONT","SELECTED_GRADIENT_START_COLOR","SELECTED_GRADIENT_END_COLOR","UNSELECTED_IMAGE_PATH","UNSELECTED_IMAGE_HORIZONTAL_ALIGNMENT","UNSELECTED_IMAGE_VERTICAL_ALIGNMENT","UNSELECTED_FOREGROUND_COLOR","UNSELECTED_BACKGROUND_COLOR","UNSELECTED_FONT","UNSELECTED_GRADIENT_START_COLOR","UNSELECTED_GRADIENT_END_COLOR","USE_SELECTED_GRADIENT","USE_UNSELECTED_GRADIENT","MOUSEOVER_TEXT"
"#TYPES"
"str","str","B","B","clr","str","I","I","clr","clr","str","clr","clr","str","I","I","clr","clr","str","clr","clr","B","B","str"
"#ROWS","13"
"SLDG-10 SLUDGE OVERVIEW","<html><center>SLUDGE<br>TRANSFER","true","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"SLDG-20 PUMPDOWN MODE","<html><center>PUMP DOWN<br>MODES","true","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Phase_2B/10-RAS_WAS/RAS_WAS","<html><center>RAS/WAS","true","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Phase_2B/19-Digest/Overview","<html><center>PRIMARY<br>DIGESTERS","true","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Phase_2B/18-Dewatering/Dewatering","<html><center>DEWATERING","true","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Tab 6","<html><center>","false","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(0,0,0,0)","color(0,0,0,0)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Tab 7","<html><center>","false","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,0)","color(43,43,43,0)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Tab 8","<html><center>","false","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,0)","color(43,43,43,0)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Tab 9","<html><center>","false","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,0)","color(43,43,43,0)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Tab 10","<html><center>","false","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,0)","color(43,43,43,0)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"Tab 11","<html><center>SETTINGS","false","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"SLDG-91 TRENDS","<html><center>TRENDING","true","false","color(170,170,170,255)","","0","1","color(255,255,255,255)","color(61,61,61,255)","font(Dialog,bold,12)","color(218,221,224,255)","color(61,61,61,255)","","-1","-1","color(43,43,43,255)","color(218,221,224,255)","font(Dialog,PLAIN,12)","color(218,221,224,255)","color(192,197,202,255)","false","false",""
"LAST - Spacer - Do Not Delete","<html><font style=""font-size:0px"">long display name - tab size is deteremined by the maximum display name and the text padding. This display name is very long to ensure it is the longest in tab data, that way text padding between tab strips can be consistent.</font><html><html><html><html><html><html><html><html><html><html><html>","false","false","color(0,0,0,0)","","0","0","color(0,0,0,0)","color(0,0,0,0)","","color(0,0,0,255)","color(0,0,0,255)","","0","0","color(0,0,0,0)","color(0,0,0,0)","","color(0,0,0,255)","color(0,0,0,255)","false","false",""

```

---

<div class="post-metadata">

**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\
**Post date:** [January 7, 2026, 2:50pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/8 "2026-01-07T14:50:05Z")

</div>

Sorry, you are now on your own. I despise cell update bindings.

---

<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [January 7, 2026, 3:08pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/9 "2026-01-07T15:08:11Z")

</div>

I thought you might say that. I will go another route and script the enabled column instead.

Do you know a simple way to set the entire column of values at once? There’s `getColumnAsList` but unfortunately there’s no `setColumnFromList` .

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<div class="post-metadata">

**Author:** ![amarks](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/amarks/32/45610_2.png) [@amarks](https://forum.inductiveautomation.com/u/amarks)\
**Post date:** [January 7, 2026, 6:03pm UTC](https://forum.inductiveautomation.com/t/property-change-null-pointer-when-saving-designer/113041/10 "2026-01-07T18:03:50Z")

</div>

I ended up adding a custom dataset property to each tabStrip to hold the “active” tab information:

Every tabStrip has 11 tabs. Any of them can be used/hidden. So I’ve got an index for the “used” tabs and a list of conditions for that tab to actually be enabled.

 ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/8/5/852c1098d7aedb24982423945ffd3e4448493f56.png)

property change script:

```python
if event.propertyName == 'selectedTab':
	
	#gateway area
	gatewayArea = system.tag.readBlocking(['Areas/Station_Area'])[0].value
	
	#selected tab index
	selectedTab = event.source.selectedTab
	
	#get selected tabData and activeTabs
	selectedTabData = event.source.parent.getComponent('Tier2_'+selectedTab).tabData
	activeTabs = event.source.parent.getComponent('Tier2_'+selectedTab).activeTabs
	
	#validate datasets
	if selectedTab and selectedTabData and activeTabs:
		
		#assign active tabs
		event.source.parent.getComponent('Tier2').activeTabs = activeTabs
		#make list from tabIndexes column of dataset
		activeTabsList = activeTabs.getColumnAsList(activeTabs.getColumnIndex("tabIndex"))
		#make list from areas column of dataset. Requires conversion to a list of lists and conversion from string to int
		activeTabAreaList = [[int(area) for area in areas.split(',')] for areas in activeTabs.getColumnAsList(activeTabs.getColumnIndex("areas"))]
		
		#for each row in the selected dataset
		for row in range(selectedTabData.getRowCount()):
			#tab is active and the current area is in the list of areas for the tab
			if row in activeTabsList and gatewayArea in activeTabAreaList[activeTabsList.index(row)]:
				#enable the tab
				selectedTabData = system.dataset.setValue(selectedTabData,row,"ENABLED",True)
			else:
				#disable the tab
				selectedTabData = system.dataset.setValue(selectedTabData,row,"ENABLED",False)
		
		#assign the dataset to the tab strip
		event.source.parent.getComponent('Tier2').tabData = selectedTabData

```

Works great. No cell update bindings