I think what happened was when it froze it already erased my art and saving my file iw simply saving the blank page. There is no way for me to see what step I was saving during the crash because I was not shown the actual step or page, just the pop up notice, so it does not matter when you did keep saving it because you're simply saving the erased art. What I should have done is saved it as another file.
I'm happy to report that the third relaunched, Rebelle did autosave a file (for my 2nd art, but not for my 1st art), the last saved step before the crash, I was able to retrieve and resaved, although I lost few steps. I did finished the 2nd art.
The square-mapping is a concern though and must be looked into what went wrong. How do the undos (command Zs) suddenly in the picture?
One account,
many possibilities