While deleting service instance in CMCC lab, we got this exception:

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2019-01-28T12:28:51.260Z|98bb6a39-e1d4-4da5-bbf9-ecb3deedcf2b| o.o.s.b.i.scripts.DoDeleteE2EServiceInstance - URN_mso_workflow_sdncadapter_callback is null
2019-01-28T12:28:51.261Z|98bb6a39-e1d4-4da5-bbf9-ecb3deedcf2b| org.onap.so.bpmn.common.scripts.ExceptionUtil - Building a WorkflowException for Subflow DoDeleteE2EServiceInstance

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This may be caused by bad variableName for getting sdncCallbackUrl, such as:

so\bpmn\so-bpmn-infrastructure-common\src\main\groovy\org\onap\so\bpmn\infrastructure\scripts\DoDeleteE2EServiceInstance.groovy 

line 117:

String sdncCallbackUrl = UrnPropertiesReader.getVariable('URN_mso_workflow_sdncadapter_callback', execution)

so\bpmn\so-bpmn-infrastructure-common\src\main\groovy\org\onap\so\bpmn\infrastructure\scripts\DoDeleteResourcesV1.groovy

line 100:

String sdncCallbackUrl = UrnPropertiesReader.getVariable('URN_mso_workflow_sdncadapter_callback', execution)

Actually the variableName should be "mso.workflow.sdncadapter.callback".