Its very unlikely your TV in incompatible, it may just require a screen resolution change within the settings.
Can you advise how your connecting the Vierra TV to the Sky Q box (eg via HDMI), secondly can you advise the model number of your TV, and also the exact error shown on display.
Looking at the technical specs I am fairly confident your model supports UHD\4K, the specs here state it supports "4K 60/50p with HDCP2.2"
Have you tried doing a factory reset on the TV then before doing anything any further setup, checking if it finds the Sky Q source?
I havent heard back from you, just wondered how you get on checking if when plugging SKy Q directly into the TV (bypassing the Yamaha), if the HDMI port shows on the source list?