'Unexpected file format' and 'Failed to load actor data'

My PC crashed suddenly while I was working on my game and then when I opened the project later on, there was an error sign 'Unexpected file format'. So I searched in google and found a solution where it was told to create a new project and replace all files with the current game files. I did it and then when I opened the project, it said 'Failed to load actor data'. Is there any way I can get back my work?

I know how it feels...

It happened to me too!
The best you can do is copy all of your graphics, audio and PBS files over to a brand new project. However, don't copy the data, editor or game files.
If you haven't made any changes to any scripts, that's good, but if you have, find the scripts you changed/added and fix them so they match the ones previously before your game crashed.

Lesson from this experience: Have a game backup, completed at least once a week.

Hope that helps,
DJ