Hello Карбасов,

Please open the preferences when you start the program so you can see in which folder the program is saving the projects. Open this folder and search the folder with the name of your project. Once found check if in the folder you can find a file called backup.iwprj

If this file is present, rename project.iwprj to old.iwprj and backup.iwprj to project.iwprj and then start the program and try to open the project again.

Please keep me updated.