"IllegalArgumentException: Unknown node id" or NullPointerException when migrating MultiInstance/SubProcess

Issue

• When migrating a process instance, I get "IllegalArgumentException: Unknown node id" or NullPointerException

2018-05-30 09:30:40,374 [main] [org.jbpm.runtime.manager.impl.migration.MigrationManager] ERROR Unexpected error during migration
java.lang.IllegalArgumentException: Unknown node id: 2 for node instance 1:5 for process instance WorkflowProcessInstance1 [processId=MultiInstance-1,state=1]
    at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:127)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.updateNodeInstances(MigrationManager.java:375)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.updateNodeInstances(MigrationManager.java:450)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.upgradeProcessInstance(MigrationManager.java:362)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.migrate(MigrationManager.java:239)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.migrate(MigrationManager.java:119)
        ...
Caused by: java.lang.IllegalArgumentException: Unknown node id: 4 for node instance 1 for process instance WorkflowProcessInstance1 [processId=MultiInstance-1,state=1]
    at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:127)
    at org.jbpm.workflow.instance.node.CompositeNodeInstance.getCompositeNode(CompositeNodeInstance.java:110)
    at org.jbpm.workflow.instance.node.CompositeNodeInstance.getNodeContainer(CompositeNodeInstance.java:114)
    at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:123)
    ... 36 common frames omitted
Caused by: java.lang.IllegalArgumentException: Unknown node id: 4
    at org.jbpm.workflow.core.impl.NodeContainerImpl.getNode(NodeContainerImpl.java:62)
    at org.jbpm.workflow.core.impl.WorkflowProcessImpl.getNode(WorkflowProcessImpl.java:50)
    at org.jbpm.workflow.core.impl.WorkflowProcessImpl.internalGetNode(WorkflowProcessImpl.java:55)
    at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:123)
    ... 39 common frames omitted

2018-05-30 09:33:27,209 [main] [org.jbpm.runtime.manager.impl.migration.MigrationManager] ERROR Unexpected error during migration
java.lang.NullPointerException: null
    at org.jbpm.workflow.instance.impl.NodeInstanceImpl.getNode(NodeInstanceImpl.java:123)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.updateNodeInstances(MigrationManager.java:375)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.updateNodeInstances(MigrationManager.java:450)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.upgradeProcessInstance(MigrationManager.java:362)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.migrate(MigrationManager.java:239)
    at org.jbpm.runtime.manager.impl.migration.MigrationManager.migrate(MigrationManager.java:119)
       ...