Advanced Fog of War - how do I turn that thing off?

Hi Today I've foolishly clicked on the Advanced Fog of War button, while in game. Now the whole screen is dark gray. I can't see anything, my players can't see anything. I thought that I can select WHICH parts of the map can be covered, but apparently Roll20 thinks that covering the whole map in gray is a good idea. It isn't, and it is incredibly irritating. Doubly so because there's no way to reverse this process. I can't get back to normal, non-gray screen. We're not using tokens, we just want to use Roll20 for rolls and map upload. This Advanced Fog of War is ruining the experience for all of us. How can I turn it off? Because I presume that there is a way to do so? I am a pro subscriber, the fact that I can't do this kind of thing with ctrl+z is seriously grating.

You should be able to turn off Advanced Fog of War and Dynamic Lighting from the page settings for any given page. It is possible you also turned on regular fog of war. (Or even Updated Dynamic Lighting). Screen shots of the page settings would help to understand what's going on.

I have them turned off. I don't know about the normal Fog of War. There's no way to check it in-game.

Those are all default campaign settings, not page settings. Actual usage of Dynamic Lighting features (including Fog of War, DL, Advanced Fog of War, and UDL) are controlled per-page in-game. Go to your page pallet (the top little blue rectangle) and click the gear icon for any given page. this is how you control whether or not any DL feature is in use. Click Page settings for page: Set DL and FoW settings.

It helped. Thank you.

Excellent!