Hello!
It should be that there is no module added to the router.
Operation:
1. First, make sure the device is powered off.
2. Right-click on "Configuration"
3. Select "Slot"
4. 1FE-TX" (100Bse-TX module with a Fast Ethernet interface)
NM-16SW (16-port switching module)
NM-4T (WAN module with 4 serial interfaces)
After you have made your choices, you can start the device.
Shown in the following picture: