Queue Notification set up is failing for HR Help Desk

Summary:

When setting up my Notification Preference for the Queue script created in Application Composer I get the error message in the image below. I want to notify all resources of new and unassigned requests but I cannot test if this script works as the Notification preference won't allow me to add it.

Content (please ensure you mask any confidential information):

Here is script i am using with the Before Update Trigger:

if (AssigneePersonName == "" || AssigneePersonName == null) {
def srQueue = QueueName;

if (srQueue != "" || srQueue != null) {
    def queueMemVo = SvcQueue?.resourceMembers;
    
    if (queueMemVo != null) {
        queueMemVo.reset();
        
        while (queueMemVo.hasNext()) {
            def queueResRow = queueMemVo.next();
            def map = new HashMap();