email script in email template

[Vedavalli]

When I'm trying to use my email script in email template
I'm getting 

Following variables are not valid or defined: ${mail_script:missing_fields_data}

Error Message

Invalid update

can I know the reason for this 

Thank you

[Vedavalli]

(function run(current, template, email, email_action, event) {

    var missingFields = [];

    // Check if state is 'On Hold' (typically value 3 — confirm in your system)

    if (current.getValue('state') == '3') {

        if (!current.getValue('hold_reason')) {

            missingFields.push("On Hold Reason");

        }

        if (!current.getValue('close_notes')) {

            missingFields.push("Resolution Notes");

        }

        if (missingFields.length > 0) {

            template.print("The following mandatory fields are missing:<ul>");

            for (var i = 0; i < missingFields.length; i++) {

                template.print("<li>" + missingFields[i] + "</li>");

            }

            template.print("</ul>");

        } else {

            template.print("All mandatory fields are filled.");

        }

    } else {

        template.print("Incident is not in 'On Hold' state.");

    }

})(current, template, email, email_action, event);

 this is the script

[Ankur Bawiskar]

@Vedavalli 

I used the same email script and it worked fine

When I click send the email goes correctly in email logs and I am able to see that in Preview Email

If my response helped please mark it correct and close the thread so that it benefits future readers.

[Ankur Bawiskar · Accepted solution]

@Vedavalli 

Thank you for marking my response as helpful.

If my response helped please mark it correct and close the thread so that it benefits future readers.