A new MIB will not add new monitors to a device if the OIDs being polled do not come back with anything. Try the following:
1. Click the configuration tab
2. Click SNMP Monitor Wizard
3. Type in the IP address of your Cisco 3850 in the section "IP address or hostname:"
4. Change the Community as needed
5. Click Next
Do you get back the system uptime?
Sorry - I never got a notification of your reply...
Yes, I do get the system uptime back.