I have SKT and I am the GM. I want to use the maps with dynamic lighting and I think that is where my issues stems from. When I load and edit things on any map as a GM the map looks as intended, but when I switch to "load as player" the map is loaded as completely black, even the objects that emit light can not be seen. When I go back to the map as a GM to try and fix some options or reveal a portion of the map it still loads to my players as a black map with nothing on it. This is an on going issue for me that is not limited just to my SKT campaign. When I created a dungeon on a test campaign and enabled dynamic lighting the same issue occured on that map as well. Step by step instructions on how to reproduce the issue.
Your computer's settings (A good place to find this info if you don't know it is Support Details ):
Mozilla Firefox 49.0 Windows 10 Javascript is enabled
My anti-virus is the basic windows defender that came installed on my laptop.