Constructing of filelist of "servername" failed - TIMEOUT(1) error on RHEL v6.6

I get the following errors on RHEL Linux servers even if I specify a single path using the directories to backup option on the Web GUI:

Errors 24.08.15 01:20 Constructing of filelist of “EIALinux1” failed - TIMEOUT(1)
Errors 24.08.15 01:20 Backup had errors. Deleting partial backup.

Firewalls are disabled on both client and server. All of my Windows Servers backups are running fine.