There's an issue with some third-party HUDs and Xenviro. Something Xenviro is doing when drawing the sky is making the HUDs disappear. As you can see from the screenshot, the info on the HUD disappears when it is against the sky.
Attaching log.txt, Xenviro log, MS32info and a screenshot.
Log.txt
MS32Info.txt
xEnviroLog.txt