Need help with major error

I just finished my assignment 2 weeks ago but only now did i realize that my file is actually unable to open (and i have already submitted it)

funny thing is, i opened a previous working version, did some minor editing, played the alice file (and recorded it as a movie using a screen cap program), then saved it and shut down alice. i then went ahead to submit the .a2w file but only now did i realize the file is no longer openable.

i get a huge error that looks like this :



i really have no idea what caused this error, however i have changed the filename manually (not save as) twice, and i THINK after the first name change, there was a 'unknown error occured' immediately after loading ends, but it disappears immediately and loads properly, and so i didn't bother to figure out what error it was

probably after i changed the filename manually the second time, it still continued working for a while unless the last save which i did not check, it died - for some reason there was no backup folder after i renamed it and repositioned it, and the only working backup i have was a few days before the final submission version

i was wondering whether ANYONE has a solution for this, probably by editing the elementData.xml inside the a2w files? help is needed PLEASE