Archive Backup issue: EC50

Hi 

We are taking archive backups of one folder on Windows 2012 server & NBU version 7.6.0.1

Archive bat file is executed from Windows task scheduler. It backups files and fails to delete those files aftrer backup, archive backup job fails with EC50.

I checked netstat on port 13782/13724 on client, there are no "TIME_WAIT".

Also client read time out on media server is already very high.

Media Server HP UX 11.31, NBU 7.6.0.3

Please suggest.