After jenkins upgrade to:
Active Choices Plug-inVersion2.6.4
ScriptlerVersion3.5
Jenkins 2.361.3
 
Jenkins is behaving so weird, Jobs missing, nextbuilder not getting reflected correctly, We are getting the following error:
 
2022-12-16 22:26:17.632+0000 [id=35]    WARNING c.c.h.p.folder.AbstractFolder#loadChildren: could not load /var/lib/jenkins/jobs/ABC/branches/Branch1.5i28jj
com.thoughtworks.xstream.converters.ConversionException: Validation failed
---- Debugging information ----
message             : Validation failed
scriptId            : The script is not allowed to be executed in a build, check its configuration!
-------------------------------
        at org.jenkinsci.plugins.scriptler.builder.ScriptlerBuilder$ConverterImpl.callback(ScriptlerBuilder.java:318)
Caused: jenkins.util.xstream.CriticalXStreamException:
---- Debugging information ----
cause-exception     : com.thoughtworks.xstream.converters.ConversionException
cause-message       : Validation failed
class               : org.jenkinsci.plugins.scriptler.builder.ScriptlerBuilder
required-type       : org.jenkinsci.plugins.scriptler.builder.ScriptlerBuilder
converter-type      : hudson.util.XStream2$AssociatedConverterImpl
path                : /flow-definition/properties/hudson.model.ParametersDefinitionProperty/parameterDefinitions/org.biouno.unochoice.DynamicReferenceParameter/script/scriptlerBuilder
line number         : 77
class[1]            : org.biouno.unochoice.model.ScriptlerScript
required-type[1]    : org.biouno.unochoice.model.ScriptlerScript
converter-type[1]   : hudson.util.RobustReflectionConverter
class[2]            : org.biouno.unochoice.DynamicReferenceParameter
required-type[2]    : org.biouno.unochoice.DynamicReferenceParameter
class[3]            : java.util.ArrayList
required-type[3]    : java.util.ArrayList
converter-type[2]   : hudson.util.RobustCollectionConverter
class[4]            : hudson.model.ParametersDefinitionProperty
required-type[4]    : hudson.model.ParametersDefinitionProperty
class[5]            : hudson.util.CopyOnWriteList
required-type[5]    : hudson.util.CopyOnWriteList
class[6]            : org.jenkinsci.plugins.workflow.job.WorkflowJob
required-type[6]    : org.jenkinsci.plugins.workflow.job.WorkflowJob
version             : not available
-------------------------------
        at org.jenkinsci.plugins.scriptler.builder.ScriptlerBuilder$ConverterImpl.callback(ScriptlerBuilder.java:323)
        at org.jenkinsci.plugins.scriptler.builder.ScriptlerBuilder$ConverterImpl.callback(ScriptlerBuilder.java:307)
        at hudson.util.XStream2$PassthruConverter.unmarshal(XStream2.java:535)
        at hudson.util.XStream2$AssociatedConverterImpl.unmarshal(XStream2.java:501)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at hudson.util.RobustReflectionConverter.unmarshalField(RobustReflectionConverter.java:456)
        at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:352)
        at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:291)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at hudson.util.RobustReflectionConverter.unmarshalField(RobustReflectionConverter.java:456)
        at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:352)
        at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:291)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:52)
        at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readBareItem(AbstractCollectionConverter.java:132)
        at hudson.util.RobustCollectionConverter.populateCollection(RobustCollectionConverter.java:87)
        at com.thoughtworks.xstream.converters.collections.CollectionConverter.unmarshal(CollectionConverter.java:81)
        at hudson.util.RobustCollectionConverter.unmarshal(RobustCollectionConverter.java:78)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at hudson.util.RobustReflectionConverter.unmarshalField(RobustReflectionConverter.java:456)
        at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:352)
        at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:291)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:52)
        at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readBareItem(AbstractCollectionConverter.java:132)
        at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.readItem(AbstractCollectionConverter.java:117)
        at hudson.util.CopyOnWriteList$ConverterImpl.unmarshal(CopyOnWriteList.java:203)
        at hudson.util.CopyOnWriteList$ConverterImpl.unmarshal(CopyOnWriteList.java:179)
        at hudson.util.XStream2$AssociatedConverterImpl.unmarshal(XStream2.java:501)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at hudson.util.RobustReflectionConverter.unmarshalField(RobustReflectionConverter.java:456)
        at hudson.util.RobustReflectionConverter.doUnmarshal(RobustReflectionConverter.java:352)
        at hudson.util.RobustReflectionConverter.unmarshal(RobustReflectionConverter.java:291)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convert(TreeUnmarshaller.java:74)
        at com.thoughtworks.xstream.core.AbstractReferenceUnmarshaller.convert(AbstractReferenceUnmarshaller.java:72)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:68)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.convertAnother(TreeUnmarshaller.java:52)
        at com.thoughtworks.xstream.core.TreeUnmarshaller.start(TreeUnmarshaller.java:136)
        at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.unmarshal(AbstractTreeMarshallingStrategy.java:32)
        at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1421)
        at hudson.util.XStream2.unmarshal(XStream2.java:189)
        at hudson.util.XStream2.unmarshal(XStream2.java:160)
        at com.thoughtworks.xstream.XStream.unmarshal(XStream.java:1399)
        at com.thoughtworks.xstream.XStream.fromXML(XStream.java:1293)
        at hudson.XmlFile.read(XmlFile.java:165)
Caused: java.io.IOException: Unable to read /var/lib/jenkins/jobs/ABC/branches/Branch1.5i28jj/config.xml
        at hudson.XmlFile.read(XmlFile.java:167)
        at com.cloudbees.hudson.plugins.folder.AbstractFolder.loadChildren(AbstractFolder.java:399)
        at com.cloudbees.hudson.plugins.folder.AbstractFolder.onLoad(AbstractFolder.java:560)
        at com.cloudbees.hudson.plugins.folder.computed.ComputedFolder.onLoad(ComputedFolder.java:221)
        at jenkins.branch.MultiBranchProject.onLoad(MultiBranchProject.java:179)
        at org.jenkinsci.plugins.workflow.multibranch.WorkflowMultiBranchProject.onLoad(WorkflowMultiBranchProject.java:84)
        at hudson.model.Items.load(Items.java:376)
        at jenkins.model.Jenkins$13.run(Jenkins.java:3423)
        at org.jvnet.hudson.reactor.TaskGraphBuilder$TaskImpl.run(TaskGraphBuilder.java:175)
        at org.jvnet.hudson.reactor.Reactor.runTask(Reactor.java:305)
        at jenkins.model.Jenkins$5.runTask(Jenkins.java:1161)
        at org.jvnet.hudson.reactor.Reactor$2.run(Reactor.java:222)
        at org.jvnet.hudson.reactor.Reactor$Node.run(Reactor.java:121)
        at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:70)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
        at java.base/java.lang.Thread.run(Thread.java:829)