Pop-up despite setting updateLegacyText to 'true'

Hi there,

My scripted Illustrator workflow involves working with a lot of files with legacy text. The script I use to open these files creates an OpenOptions() object, to which updateLegacyText is set to true.

var fileRef = File("c:\script_path\myfile.ai")

var optRef = new OpenOptions();

optRef.updateLegacyText = true

var docRef = open(fileRef, "null", optRef);

When I run this script using ExtendScript Toolkit, no problem -- the file opens and all the legacy text is updated.

However, when I run the script from the command prompt...

illustrator.exe -run c:\script_path\my_script.jsx

Everything works EXCEPT I still get a pop-up asking whether or not I want to open legacy text.

This may seem like a small inconvenience, but it means that this process cannot be fully automated. If I need to process dozens of files, I would need to be present to click "Okay" at each pop-up.

I find this behaviour odd, since it works fine when run from the ExtendScript Toolkit. Is anyone aware of this problem? I am using the latest version of Adobe CC 2017.

Thank you very much for any help you can provide