Unexpected file format - Lost skb file

I got an “Unexpected File Format” error. I tried everything I know, including importing/renaming etc but the error still exists and i lost the skb file also

Is there anyone who can help me find why it happens, and even fix it?
Trying to help my dad, its quite important.

Thank you so much!

The file is attached in the following address:

A common cause is saving and opening a file that is stored on a non-local drive (cloud).

I tried recovering something from the file, but didn’t get anything.

Hi everyone , can i request help recovering my file too. i cant open both skp and skb file. i dont know what else to do. i cannot lose this amount of work at this time. :frowning:pls help