Unable to update assignee using scriptrunner Script file under SCRIPT ROOT

[Arnstein_Jensen]

Hi,
We use Jira inline script to set Assignee to defined Customfield. The Groovy script works fine when running as inline script written in the postfunction in workflow. When we put the same script in a file under Script root (Script editor) and select the runtime script file in the same workflow postfunction, the script fails to set the assignee. There is no error message. (using Jira Software 8.5.1  server/data center).

import com.atlassian.jira.component.ComponentAccessor;
import com.atlassian.jira.issue.CustomFieldManager;
import com.atlassian.jira.issue.Issue;
import java.sql.Timestamp;
import com.atlassian.jira.issue.fields.CustomField;
import com.atlassian.jira.issue.IssueManager;
import com.atlassian.jira.issue.MutableIssue;
import com.atlassian.jira.user.ApplicationUser;
import com.atlassian.jira.issue.index.IssueIndexingService;
import com.atlassian.jira.security.roles.ProjectRoleManager;

CustomFieldManager customFieldManager = ComponentAccessor.getCustomFieldManager();

CustomField CFAutoMelding = ComponentAccessor.getCustomFieldManager().getCustomFieldObject(12903L);
Object selectedValues = issue.getCustomFieldValue(CFAutoMelding);
def selectedValuesString = (String)issue.getCustomFieldValue(CFAutoMelding)

if (selectedValues == null){
// Automatisk message disabled

} else {

CustomField bestiller = customFieldManager.getCustomFieldObject(10911);
Object bestillerValue = issue.getCustomFieldValue(bestiller);
if(bestillerValue != null) {
issue.setAssignee(bestillerValue);
}
// Automatisk message aktivated

def commentManager = ComponentAccessor.getCommentManager()
def user = ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser()
def assignee = issue.getAssigneeUser().getName()


def projectRoleManager = ComponentAccessor.getComponent(ProjectRoleManager)
def groupManager = ComponentAccessor.getGroupManager()
def role = projectRoleManager.getProjectRole("Developers")

if (issue.assigneeUser) {
if (assignee != user.name) {
commentManager.create(issue, user, "[~$assignee] Issue updated by [~$user.name] and your are assigned this issue", true);
}
}
}