I have been having an odd issue with the areaportals in my map, or rather the doors around them. Here is one in particular that is giving me trouble. I have a pair of doors with a func_areaportalwindow in the middle. Yes I know usually to use func_areaportal, but in this case I am using a func_brush and some env_lightglow's to create a blinding effect. Anyway, one or both of the doors will just 'disappear' from view, revealing the sky instead. The doors aren't actually going anywhere, they just stop being rendered and its all based on angles. You can stand in one spot and it looks normal, but move slightly and a door disappears. Some picture: Both Doors shut, rendering normally: Both doors shut, one door 'missing': Both doors open, white func_brush visible Both doors open, and one 'missing' For reference, even though no errors Can anyone help me stop them from disappearing? Compile log shows no errors, and Alt+P gives nothing either.