[BUG]: LAMBDA tasks not working after upgrade to 3.0.6

[jansonz]

Describe the bug
After upgrading from 2.30.4 to 3.0.6 LAMBDA tasks have started with the following error:

{
   "error": "Cannot invoke \"javax.script.ScriptEngine.createBindings()\" because \"com.netflix.conductor.core.events.ScriptEvaluator.engine\" is null"
}

The task JSON:

{
   "taskType": "LAMBDA",
   "status": "FAILED",
   "inputData": {
      "computed_external_id": "xxxx.xxxx",
      "scriptExpression": "if ($.wf_input_external_id == null){ return {external_id: $.computed_external_id} } else { return {external_id: $.wf_input_external_id} }",
      "wf_input_external_id": "xxxx.xxxx"
   },
   "referenceTaskName": "get_external_id_1",
   "retryCount": 0,
   "seq": 4,
   "pollCount": 0,
   "taskDefName": "LAMBDA_TASK",
   "scheduledTime": 1625225405021,
   "startTime": 1625225405021,
   "endTime": 1625225405042,
   "updateTime": 1625225405042,
   "startDelayInSeconds": 0,
   "retried": false,
   "executed": false,
   "callbackFromWorker": true,
   "responseTimeoutSeconds": 0,
   "workflowInstanceId": "4abdaef1-1909-4470-ae3b-63c18583983f",
   "workflowType": "vott_vod_ingest",
   "taskId": "15ac5679-f674-494a-b62e-4a06817472ea",
   "reasonForIncompletion": "Cannot invoke \"javax.script.ScriptEngine.createBindings()\" because \"com.netflix.conductor.core.events.ScriptEvaluator.engine\" is null",
   "callbackAfterSeconds": 0,
   "outputData": {
      "error": "Cannot invoke \"javax.script.ScriptEngine.createBindings()\" because \"com.netflix.conductor.core.events.ScriptEvaluator.engine\" is null"
   },
   "workflowTask": {
      "name": "LAMBDA_TASK",
      "taskReferenceName": "get_external_id_1",
      "inputParameters": {
         "wf_input_external_id": "${workflow.input.external_id}",
         "computed_external_id": "${get_provider_configuration_1.output.response.json.properties.externalid_prefix}.${get_assetid_1.output.response.json.matches[0].groups.assetid}",
         "scriptExpression": "if ($.wf_input_external_id == null){ return {external_id: $.computed_external_id} } else { return {external_id: $.wf_input_external_id} }"
      },
      "type": "LAMBDA",
      "decisionCases": {},
      "defaultCase": [],
      "forkTasks": [],
      "startDelay": 0,
      "joinOn": [],
      "optional": false,
      "defaultExclusiveJoinTask": [],
      "asyncComplete": false,
      "loopOver": []
   },
   "rateLimitPerFrequency": 0,
   "rateLimitFrequencyInSeconds": 0,
   "workflowPriority": 0,
   "iteration": 0,
   "subworkflowChanged": false,
   "queueWaitTime": 0,
   "loopOverTask": false,
   "taskDefinition": null,
   "logs": []
}

Details
Conductor version: 3.0.6

[jansonz]

Managed to resolve the issue by downgrading to Java 11 as it seems nashorn is discontinued on newer Java versions. Something to note for the future I guess.

[apanicker-nflx]

@jansonz Nashorn is deprecated in JDK 11 and will be removed in future versions. We are looking for contributions for this upgrade in #2312 . Please let us know if this is something you would be interested in contributing. Thanks