Bug: Player able to see whole map with dynamic lighting

It seems like there might be a Chrome extension that updated and is now interfering with things. We've had a few people report this issue suddenly over the past few days, but a couple reported that clearing their extensions or switching to Firefox fixed it. Can you let us know if the player in question has any Chrome extensions installed?

When Dynamic Lighting breaks, it's typically due to something interrupting the JavaScript that's running in the background to obscure the map to the player. Browser addon/extensions are normally culprit #1, but if you're running a very recent version of Chrome, sometimes they introduce some bugs that interfere with Roll20's processes. I am currently running Chrome version 55.0.2883.87 m (64-bit) and dynamic lighting appears to be working as expected. If you're using one of the Beta Chrome builds, you might want to see if downgrading it to a stable version to see if that fixes things. What version of Chrome are you using?