Save the FLA before reopening it.
Even saving the file changes are not retained.
Well, I just tested using JSFL to change the name of a moveclip, and it survived a save/load just fine.
Maybe try manually renaming a couple of movieclips before saving and see if those changes don't get saved either.
I tried changing another property of the Movie Clips (e.g. alpha) after renaming them and so the changes were saved.
But if I only change the names with the script, save the file and then reopen it, changes are gone.
This is a bug and I think it should be reported to Adobe.
I tried running your JSFL script on a bunch of selected symbol instances on stage.
I then saved,closed and reopened the file and the name changes were present as expected.
Can you please specify how exactly to recreate the issue, if any? Please also share your test file, if it happens on a specific file only.
Hi, Nipun. Thanks for your answer.
Here is a video showing what is happening:
First, I run the script without altering any other property. In this way the names are not kept when I reopen the FLA. Then, I run the script and alter the alpha property of all instances. In this way the names are kept when I reopen the FLA.
And here are the files so you can take a look: https://drive.google.com/drive/folders/0BxplDXBQ7gXzLUpCd3ZoaDNuWVU?usp=sharing
I tested in two FLA and the problem persisted.
Thanks for sharing the video!
It seems the name changes were correctly getting saved if you're working on the main timeline. However, in your video you're working inside a Symbol - which is when the problem happens.
I'll log it as a bug internally.
Thank you, Nipun!