Can't connect after upgrading to V3 Hub

Hi, when my V1 Hub stopped working, I got a V3 model and managed to add it to my devices. I tried to connect two of my old devices today (a light switch and a smoke detector) with no luck at all. I tried repairing the z-wave network and turning secure mode off and I still cannot get anything to connect to the hub. Any suggestions? Thanks.

brand/model of the devices? if z-wave devices, did you try a z-wave exclusion on them through the app first and then try to add them?