# NPE : Error processing tag value change - tags json import **URL:** \ **Category:** Ignition\ **Tags:** ignition81\ **Created:** [January 19, 2023, 3:26pm UTC](https://forum.inductiveautomation.com/t/npe-error-processing-tag-value-change-tags-json-import/68794 "2023-01-19T15:26:42Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\ **Post date:** [January 19, 2023, 3:26pm UTC](https://forum.inductiveautomation.com/t/npe-error-processing-tag-value-change-tags-json-import/68794/1 "2023-01-19T15:26:42Z")
**Ignition 8.1.23 and before** when I create tags instances of UDT (with json import), I have a few of those error: I can't figure out which udt def is concerned, (a quite large file is imported) because the gateway logs doesn't mention any tags. Perhaps @ggross have some ideas of the cause of those error ? ```auto INFO | jvm 1 | 2023/01/19 12:58:01 | E [t.e.core] [11:58:01]: Error processing tag value change. INFO | jvm 1 | 2023/01/19 12:58:01 | java.lang.NullPointerException: null INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.actors.factories.scaling.ValueScaler$EngLimitEnforcer.checkBounds(ValueScaler.java:381) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.actors.factories.scaling.ValueScaler$EngLimitEnforcer.scale(ValueScaler.java:387) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.actors.factories.scaling.ScalingActorFactory$ScalingActor.processValue(ScalingActorFactory.java:117) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.ExecutableTag.valueChanged(ExecutableTag.java:429) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.actors.factories.value.AbstractValueGeneratingActor.fireValueChange(AbstractValueGeneratingActor.java:73) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.actors.factories.value.AbstractValueGeneratingActor.setListener(AbstractValueGeneratingActor.java:40) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.ExecutableTag.configureActors(ExecutableTag.java:858) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.ExecutableTag.applyPropertyChangesToTag(ExecutableTag.java:631) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.BasicTagDefinition.managePropertyChanges(BasicTagDefinition.java:829) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.BasicTagDefinition.startPropModel(BasicTagDefinition.java:514) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.BasicTagDefinition.activate(BasicTagDefinition.java:980) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.BasicTagDefinition.startupInternal(BasicTagDefinition.java:964) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.BasicTagDefinition.startup(BasicTagDefinition.java:950) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.AbstractTopLevelUdtTag.configureChild(AbstractTopLevelUdtTag.java:429) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.AbstractTopLevelUdtTag.manageMemberChanges(AbstractTopLevelUdtTag.java:253) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.AbstractTopLevelUdtTag.onSuperMembersChanged(AbstractTopLevelUdtTag.java:174) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.onSuperMembersChanged(TypesFolder.java:589) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.onValidityChanged(TypesFolder.java:536) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.setValidityState(TypesFolder.java:514) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.refreshValidity(TypesFolder.java:430) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.setSuperType(TypesFolder.java:359) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.notifyParentTypeChanged(TypesFolder.java:337) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder$AbstractTypeNode.attach(TypesFolder.java:329) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.TypesFolder.registerComplexNode(TypesFolder.java:114) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.complex.AbstractComplexTagDefinitionNode.startupInternal(AbstractComplexTagDefinitionNode.java:120) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.BasicTagDefinition.startup(BasicTagDefinition.java:950) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.nodes.FolderNode.startup(FolderNode.java:322) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.TagEvaluationManagerImpl.processNewTag(TagEvaluationManagerImpl.java:577) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.TagEvaluationManagerImpl.processEditInternal(TagEvaluationManagerImpl.java:407) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.runtime.TagEvaluationManagerImpl.processEdit(TagEvaluationManagerImpl.java:321) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.TagProviderImpl.saveTagConfigInternal(TagProviderImpl.java:813) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.TagProviderImpl.lambda$importTagsAsync$25(TagProviderImpl.java:1140) INFO | jvm 1 | 2023/01/19 12:58:01 | at com.inductiveautomation.ignition.gateway.tags.TagProviderImpl.lambda$exec$5(TagProviderImpl.java:462) INFO | jvm 1 | 2023/01/19 12:58:01 | at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) INFO | jvm 1 | 2023/01/19 12:58:01 | at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) INFO | jvm 1 | 2023/01/19 12:58:01 | at java.base/java.lang.Thread.run(Unknown Source) ``` ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/b/9/b97f5756fe48bd4cada049bb85df2abbf4cfc756.png) ---
**Author:** ![ggross](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/ggross/32/12668_2.png) [@ggross](https://forum.inductiveautomation.com/u/ggross)\ **Post date:** [January 19, 2023, 5:16pm UTC](https://forum.inductiveautomation.com/t/npe-error-processing-tag-value-change-tags-json-import/68794/2 "2023-01-19T17:16:25Z")
Based on where the error is occurring, I think it will be occurring on a tag with a Scale mode set (likely with a clamping mode set) that somehow is getting a `null` qualified value. I know that is pretty vague, but hopefully that narrows the potential culprits a bit. Garth ---
**Author:** ![mazeyrat](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/mazeyrat/32/10955_2.png) [@mazeyrat](https://forum.inductiveautomation.com/u/mazeyrat)\ **Post date:** [January 19, 2023, 6:28pm UTC](https://forum.inductiveautomation.com/t/npe-error-processing-tag-value-change-tags-json-import/68794/3 "2023-01-19T18:28:30Z")
Thanks, I will try to only import few tags candidate based on your track.