Solution for this topic
I just ran the latest Unyson update and no longer experience this issue. Could be a Chrome update involved too, not sure.
I just got this theme as well and its mostly great – I noticed a similar issue however that the Footer & Notifications settings are blank, while all other theme settings load fine.
I believe (at least in my case) this is an issue of mixed content (non-SSL) resources being blocked by Chrome. If you turn off that privacy setting or use another browser it will work, but I imagine its also a fairly easy bug to fix in a future release?