I am getting a visual graphics glitch in RC 1.68.140267. Sometimes a black line appears at the horizon-level when moving around your view. It is only visible momentarily but if you move your view in steps pixel by pixel, I managed to photograph it.
I have been able to reproduce it after a restart of Arma 3.
The line in the screenshot occurred 12:21:27 but there is no evidence of any corresponding errors in the log.