Appeared error when backup data.

Hello,

We have installed BE 2012 on Windows 2012 server, we know that is incompatible, but we also have other using this situation with no problem.

I tried to run one-time backup of FTP server with 80GB data to local hard disk, it will pop-up following error with 2-3times, but the backup will be finish. 

I want to know what's this error for ? can someone help ?

Thanks