TypeError: element has no properties

[SillyVyxia]

Version: Flash CS6
Platform: Windows
Error:

BTA 1.2.0
The following JavaScript error(s) occurred:

At line 302 of file "BetterTextureAtlas.jsfl":
TypeError: element has no properties

When trying to export multiple symbols, BTA attempts to pack them all in one temporary symbol, which is where the error occurs, but it isn't consistent.
Sometimes it happens on the first frame, Sometimes it happens in the middle, and sometimes it happens at the end.

element.symbolType = "graphic"; // make sure all frames get exported

This is where it occurs, my only guess on why would be that it may need some time to load the element in cs6, for whatever reason.
I get that the CS6 code isnt actively maintained, but this bug makes it unusable.

[MaybeMaru]

Would you mind sharing some fla file that replicates this behaviour? Im unable to recreate it myself with the flas I have in Flash CS6.

[SillyVyxia]

GF_ass_sets.zip
This should replicate it.

[MaybeMaru]

Does the error occur when trying to export some specific symbol? Trying to export the first symbols that came to mind worked fine

[SillyVyxia]

I'm unsure, it's seemingly random what symbol breaks.
If it helps, here is all the symbols I was trying to export:
"GF Dancing Beat", "GF Dancing Beat Hair blowing", "GF Dancing Beat Hair Landing", "GF Down Note", "GF Duck", "GF Cheer", "GF FEAR", "GF left note", "GF Right Note", "gf sad" and "GF Up Note".

[MaybeMaru]

Ok so trying to test this on CS6 I ran into some crashes that I was able to fix with the latest commit.
They aren't related to the crash line mentioned here, but it'd be really helpfull if you could give it a try, may be resolved.
Still, I'd heavily recommend grabbing a copy of newer Animate if possible for exports because Flash CS6 and lower is just a complete buggy mess to work with for this script.