App opens, but nothing shown in HMD

[FruitFace]

Once SteamVR is running, I run the app, and the window opens on the desktop. There is nothing shown, but a backdrop in the window on the desktop. In the HMD, I only see the normal Steam environment. I have tried both Steam Beta, and the Release branch, with the same results. I also deleted and downloaded ChaperoneTweak again, with the same results.
output_log.txt

[FruitFace]

Turns out running Steam as administrator was causing the issue. Once I disabled this, ChaperoneTweak is functional once more.