My project crashed and when I open it again, I have this message:
“Document not well-formed.
Line 1, column 1 (fatal):
Extra content at the end of the document.”
My version is 1.3.16 Developement.
How do I fix it? I spent 2 hours making this project 
I’m really sorry to hear/read that!
Can you see the .sif/.sifz file size?
By the way, do you remember your last action before Synfig crashed?
The size is 188 byte. Hmmm. I was saving the project about every 30 seconds by pressing ctrl+S. Before crash I just watched animation preview.
Ouch!
Are you using windows/linux/mac? There is a (little) chance you can find a previous copy in ~/.config/synfig/tmp/ on Linux. I’m not exactly sure where is it on Windows, but it would be inside the extraction/installation folder and named “tmp”.
The animation preview via Preview Dialog or inside the main window (=work area)?
Inside the main window. I have win 10, I’ll try to find temp folder now.
The tmp folder is empty
I saw somewhere that .sifz file is just the same as .xml and I should open it as .xml and do some operations with code. Does it make sense or I lost my project for ever?
OK nevermind. I just made all animation again. Now I am saving the same project with different names every 5 minutes so I won’t totally lost my progress.
For the file size, I think it’s really corrupted