# \[BUG / QUESTION\] Perspective Log Error

**URL:** <https://forum.inductiveautomation.com/t/bug-question-perspective-log-error/21408>\
**Category:** Ignition Early Access\
**Created:** [December 13, 2018, 8:57pm UTC](https://forum.inductiveautomation.com/t/bug-question-perspective-log-error/21408 "2018-12-13T20:57:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![christopher.green](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@christopher.green](https://forum.inductiveautomation.com/u/christopher.green)\
**Post date:** [December 13, 2018, 8:57pm UTC](https://forum.inductiveautomation.com/t/bug-question-perspective-log-error/21408/1 "2018-12-13T20:57:56Z")

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What does this translate to? I’m having this spool out in the log every ms or so.

```auto
java.lang.IllegalStateException: Cannot replace child, no parent

at com.inductiveautomation.perspective.gateway.property.PropertyTree$Node.replaceMe(PropertyTree.java:498)

at com.inductiveautomation.perspective.gateway.property.PropertyTree$StructuralNode.write(PropertyTree.java:587)

at com.inductiveautomation.perspective.gateway.property.PropertyTree$MapNode.write(PropertyTree.java:674)

at com.inductiveautomation.perspective.gateway.property.PropertyTree.lambda$write$3(PropertyTree.java:406)

at com.inductiveautomation.perspective.gateway.property.PropertyTree.writeImpl(PropertyTree.java:426)

at com.inductiveautomation.perspective.gateway.property.PropertyTree.write(PropertyTree.java:406)

at com.inductiveautomation.perspective.gateway.property.PropertyTree.write(PropertyTree.java:402)

at com.inductiveautomation.perspective.gateway.model.ElementBindingHarness.writeToTarget(ElementBindingHarness.java:65)

at com.inductiveautomation.perspective.gateway.model.AbstractBindingHarness.valueReady(AbstractBindingHarness.java:318)

at com.inductiveautomation.perspective.gateway.model.AbstractBindingHarness.lambda$processPublishedValue$0(AbstractBindingHarness.java:193)

at com.inductiveautomation.ignition.common.util.ExecutionQueue$PollAndExecute.run(ExecutionQueue.java:123)

at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)

at java.base/java.util.concurrent.FutureTask.run(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.base/java.lang.Thread.run(Unknown Source)

```

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<div class="post-metadata">

**Author:** ![cmallonee](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/cmallonee/32/6416_2.png) [@cmallonee](https://forum.inductiveautomation.com/u/cmallonee)\
**Post date:** [December 14, 2018, 3:26pm UTC](https://forum.inductiveautomation.com/t/bug-question-perspective-log-error/21408/2 "2018-12-14T15:26:46Z")

</div>

Hard to tell without a View to examine, but it looks like a property is bound with some kind of polling (maybe a SQL tag?) and part of that binding (possibly through a transform) looks to be writing to a property which can’t be located. For the open View which is causing this (record all open View names, close them all, then open them one-by-one at a time until you see this again) identify any properties which are using bindings which would poll, and look to see if any of those bindings are targeting a **different** property as part of the binding. If any are, then check that the target property (and its parent) is in fact in place.