There are various reasons for a device configuration failure: incorrect credentials, network connectivity, device configuration, insufficent priviledge.
1. In the device policy, is the 'Configuration Backup' monitor enabled?
2. Select the device>right click>Settings>Verify Monitoring Status. Is there an error on the monitor?
3. Select the device>right click>Settings>Manage Credentials. Is there a Telnet/SSH credential configured?
No - create a valid read/write credential
Yes - Test the credential by manually logging into the device. Make sure the credential has read/write priviledge.