Result:
fovTop=NaN; fovLeft=NaN;
You should set these values in your Arma 3 profile config which can usually be found at:
~/Documents/Arma 3 - Other Profiles/[your profile name]
It’s important to note that changing these values will mess with the ranging and zooming of every scope in the game, especially overlay-based scopes. Those do not scale with the viewemodel and will be inaccurate when the zoom is non-default.
I recommend the following values:
Infantry/Normal Ops: 90
Infantry/CQB (KotH, etc): 95-120 (your mildots will be inaccurate)
Vehicles/Helicopters/Jets: 95-110 (higher values can make it difficult to see mines, enemies)