After working with your software (that it looks good) for almost 1 hour , I saved the project. When I open it it’s empty. I tried several times the same and it comes empty. But the file size is like 500 Kb.
One possible problem is that there are special characters in the image filenames.
Please only use A-Z, a-z, 0-9, underscore _ and dash - in the image and project filename.
Special characters, for example, accented letters, &, *, !, # will cause problems in the software and in the web browser.