Hiding of fog has been removed from Hide It! and moved to Render It! for more flexibility. If you want to reproduce the same effect as in previous version of Hide It! then subscribe to Render It!, go to Options > Environment and change the following values:

Hide Pollution Fog:
Pollution Amount = 0

Hide Volume Fog:
Fog Density = 0

Hide Distance Fog:
Color Decay = 1

Hide Edge Fog:
Edge Distance = 3800