How do I open a failed project?

Friday i was working in the project without any issue, monday morning i tried to open the file and I receive this error:

"Failed to open project. Check it is a valid Construct 3 folder project."

Not sure why is failing, not sure neither what exactly is 'sandbox', my latest backup was like 20 days ago and the project was almost ready :$

I believe you didn't capture the error in the console log.

When you get that message "Failed to open project", open the console, scroll to the bottom and check the last few error messages.

i took another capture of the whole console, this is all the info i have as feedback from the error, still not sure what/why is failing

Maybe there's something wrong with those PNG images mentioned in the log. Although when an image is missing, the error is usually different, it looks like this:

[Project] Exception opening: Error: missing file path 'images\building4x3-animation 1-002.png'

Try renaming the project to .ZIP, extracting all files and opening it in C3 as a folder project. Check that those image files exist and you can preview them. Try running C3 in a different browser.