Re: The selected file is not a valid Moodle backup file and can't be restored.

I did the following

I installed Moodle 3.9 on a new server and when I try to backup/resore form Moodle 3.7 I got the same error message.

I think the problem is in exporting the backup file from the source server (Moodle 3.7) because I tried to do  backup/restore to source server I got same error message.

below the content of .mbz file, I used 7z to extract it, I can't figure what I miss : (