Could you select the "Cisco IOS - SSH Capable" node on the Explorer tab and select Information tab on Contents panel and look at Device Configuration Transfer Settings -> Default Communication Mode?
Could you also check Communication Mode on device model level under its Information tab -> Network Configuration Manager -> Local Communication Configuration subview?
If you are using SNMP/TFTP Communication Mode please make sure you have set WRITE SNMP Community String on the device model and TFTP server has been running on SpectroSERVER machine and configure under Configuration Manager -> Information tab -> TFTP Configuration subview.
If you are using SSH/SCP and having problem, could you try the following command using the same specified user on bash shell (outside of Spectrum application) on the SpectroSERVER machine.
scp <user>@<router s IP>:running-config .
scp firstname.lastname@example.org:running-config .
Note: please notice the dot character at the end of the command line is required.
The command will prompt you to key in user’s password and you will get the configuration from the router provided the user has been configured with privilege 15 and SSHv2 and SCP has been configured properly.
If running this works, then NCM should work too using SSH/SCP Communication Model. If no, then it may be network or router’s configuration issue.