Zip File From Snapshot Pro Not Have All The Files

Hello Sir,

We tried to make backups for our sites by snapshot pro and in some files the snapshot process stop without completing the backup like "www.newavenue-egypt.com" and some times it complete it's process and create the ZIP file but after downloading the file we find that each database table is in separate SQL file and the www folder have only the uploads, CSS, sitemap and htaccess file but not have the plugins files and the themes files!

Also when trying to open the downloaded ZIP file we got this error "! C:\Users\HP\Downloads\snapshot-1478511622-161107-094022-a3b40774.zip: Unexpected end of archive" in the opening

Thanks!