Recently (meaning the past few months) a bug has cropped up where the eye shaped fog of war option in the menu at the top left are replaced with a small blank space that does not respond to being clicked on. For some reason, it looks like it is flagged as a 'hidden' legacy item. I believe this is an error, since manual fog of war does not seem to be implemented in the new dynamic lighting system yet, meaning that the 'legacy' option is actually the only way to manually reveal areas. GMs can work around it by double-tapping the 'R' key, which selects the 'reveal' tool and causes the icon to be displayed. Until a method is available for converting to the newer options though, I think this flag needs to be switched back off.