Here is my Script with Jira version 8.11 and Script Runner Version 6.12
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.MutableIssue
def project = ComponentAccessor.projectManager.getProjectByCurrentKey("HC")
def loggedInUser = ComponentAccessor.jiraAuthenticationContext.loggedInUser
def parentIssue = ComponentAccessor.issueManager.getIssueByCurrentKey("HC-1");
MutableIssue issue = ComponentAccessor.issueFactory.issue
issue.projectObject = project
issue.summary = "This Is Sub-Task"
issue.issueTypeId = 10006
issue.setReporter(loggedInUser)
issue.setReporterId("dhandaresanjay@gmail.com")
issue.assignee = loggedInUser
ComponentAccessor.issueManager.createIssueObject(loggedInUser,issue)
ComponentAccessor.subTaskManager.createSubTaskIssueLink(parentIssue,issue,loggedInUser)
But getting this error
ERROR [workflow.AbstractScriptWorkflowFunction]: Workflow script has failed on issue HC-7 for user 'sanjay'. View here: http://localhost:8080/secure/admin/workflows/ViewWorkflowTransition.jspa?workflowMode=live&workflowName=Software+Simplified+Workflow+for+Project+HC&descriptorTab=postfunctions&workflowTransition=1&highlight=4 java.lang.AssertionError: Errors: {reporter=The reporter specified is not a user.} Error Messages: []. Expression: validationResult.valid