Are you refering to the project file or the source video/image files?
If the project file, did you regularly save the project while editing?
If so the file will be in the location you saved to and there may be up to 10 backups with file names ending in _BAK0.MV_ through to _BAK9.MV_ that you can load and resave the project - note the 0 - 9 numbering does not signify which is the latest as when 9 is reached the numbering sequence starts again with 0, use the date/time created to determine the 'age' of the backups.
Have the source video/images/audio files used in the project been transferred to an internal drive or an external USB drive ?
If a USB drive check that the files are still there, this will awaken the drive if it, or the USB port, have gone to sleep