What does this symbol mean?

I made a new version of the file,
worked on it,
then opened up the original version and now all the layers with that weird symbol are empty.


Is there a way to get them back?

Does it have to do something with the “other version” I made (where those layers dont exist?)



Is the new version on the same folder as the original file? I’m not sure, but I think that when you create a new version in other folder it will be unable to find the drawings and elements. The best way to create a backup is to copy all the project folder.

Yes, but I didn’t do this, the program did it on it’s own when I chose “Save as new version”.
It just automatically made the file inside the other folder without asking,

Still, I have no idea what the symbols mean and where has my animation gone.

The symbol means the layer is synced with another layer. If you change the timing of one of the synced layers all layers will change. So it could happen that you removed the exposure of another layer and that cleared that one?

More about sync layers: https://docs.toonboom.com/help/harmony-15/premium/timing/sync-two-layers.html