Flow Designer inline scripting error

I am trying to update a field on a CI form based on the current value using fd.data object, but I am getting an error:

"Flow Designer: attempting to use undefined input = 'current' from Append Comment: no thrown error"

var today = new Date().toLocaleDateString();
var shortDesc = fd_data.trigger.current.short_description;
shortDesc = shortDesc + "/n" + " ---Good bye " + today;

I did see a similar issue where "current" is not available under subflows, but I am getting the same error when using it under the main Flows.,

Any directions OR guidance greatly appreciated.

thanks