Well, another day - another UCS error. Out of the blue, one of our chassis started displaying that one PSU had failed, however the UCS was showing no PSU had failed 🤷 
Well, as it turns out - this is yet another known bug in 2.0.2(r). You’ll either have to unplug and plug all the power cables (that’s four) in a maintainance window - or simply change the Equipment Power Policy (found in the Root of your UCS, tab Policy) 
from “N+1” to “Non Redundant”; wait a minute or two till the error is “fixed” and then change it back to “N+1”. Problem solved for now … 😀