Doug E.'s description of March 14 (here: <a href="https://app.roll20.net/forum/permalink/9900485/" rel="nofollow">https://app.roll20.net/forum/permalink/9900485/</a>) is accurate to the behavior that I currently experience, using a dummy account. For the sake of making my use case and expectations as clear as I can: 1) I am using UL to emulate the vision mechanics used in D&D 3.X/Pathfinder 1E. In those systems, a light source has an expressed light radius, in which it sheds bright light. In most cases, a "shadowy" area equal to this radius is also present around the radius. In the example of a torch, this is a 20-ft. radius of bright light, surrounded by an additional 20 ft. radius of shadowy light, for a total 40 ft. radius. It is effectively a "bull's eye" configuration with a total diameter of 80 ft. UL has no trouble configuring a light source that covers these parameters. I can set the toggles under Token Emits Light to on for both bright and low light, with both at 20 ft., and I have torchlight. Easy-peasy. 2) If a character token is configured to have normal vision--no night vision, light modifier 100%--then the light source described in 1) appears as expected. This accurately models 3.5/PF 1 vision mechanics for humans, as well as many other creature types. 3) If a character token is configured to have normal vision plus 60 ft. night vision, the light source appears as expected, which means that if the token is more than 60 feet from the edge of the light source's shadowy illumination, it can see the illuminated areas the same way as in 2), and it also sees a 60 ft. radius via its night vision. This accurately models 3.5/PF vision mechanics for a dwarf, half-orc, or similar creature that has normal vision plus what those systems call "darkvision." 4) If a token is configured with Light Modifier 200%, it sees bright illumination in a 40 ft. radius around the light source from 1), and no low illumination at all . If I move the light source, then the token's vision changes to show a bright radius of 40 ft., and low illumination radius of 40 ft., which is the expected behavior. If it is performing as expected, this configuration emulates the 3.5/PF mechanic for "low-light vision" which should allow a creature such as an elf to see twice as far as a human under conditions of shadowy illumination. 5) If a token is configured with Light Modifier 200% and night vision 60 ft., the night vision seems to be completely unaffected by the light modifier. This is as expected. The buggy behavior described in 4) is still evident, however. Based on this odd behavior, I assume that case #4 is a bug. To duplicate it, you must set up a light token as described, place it on the map, and then create a token using Light Modifier 200%. The buggy behavior is evident regardless of whether you set up a new token or use a preconfigured one that you drag from the Journal for a character. Screenshots follow; I have used a blue tint with night vision for these, in order to make it easy to see the difference. Please note that in all cases, the bugged behavior seems to require me to move the light-emitting token to end it for that token and get the light sources to behave as expected. That is, it's not a workaround where I can fix one and it fixes all of them. Above, the GREEN token is configured with normal vision. Light sources at the north and south are behaving as expected. The green token is configured with night vision, tinted blue to make it easy to differentiate. This functions as expected. The green token is configured with Light Modifier 200%. It is bugged; the radius on the northern light source is set to 20 ft. bright and 20 ft. low, as described above, but it is visible as 40 ft. bright with no low. Green has the same settings as before, because it is the same token. I moved the northern light source slightly and then moved it back, and the bugged behavior gave way to expected 40 ft. bright, followed by 40 ft. low illumination. The southern light sources are still bugged, because I didn't touch them. This behavior is not intermittent for me; it happens without fail, anytime I use Light Modifiers. And if I refresh the page for Roll20, the bugged behavior immediately returns, even after I have fixed it by moving light sources. In addition to this, if I set up two tokens, one with a 200% Light Modifier, and one with only 100%, and I set them both to be "Edited and Controlled By" by the same player (or all players), both tokens see as if they had a 200% light modifier. This is not as expected. Given that I am a customer (that is, I pay actual money TO YOU), I should not be doing your QA work for you. I don't wish to be unpleasant or dwell excessively on it, but it is not at all acceptable that your users are doing a difficult, time-consuming task for you, without compensation, and Roll20's conduct by bringing LDL to sunset while UDL is as half-baked and buggy as it is has me contemplating other solutions for my game. I've sunk a lot of time into this platform getting maps set up with dynamic lighting, or I would already be gone. The fact that a customer is having to walk you by the hand through bugs that are so obvious and so easy to reproduce is pretty unacceptable.