Players seeing through dynamic lighting

I am running a game with 5 players. 2 of them live together and play on seperate laptops using the same Internet. One of these players seems to be able to see through all the dynamic lighting layer. None of the lines placed block their line of sight and the map always appears to be globally lit for them even when global illumination is turned off. The character has no darkision or anything similar and so shouldn't be able to see anything in the dark. It has left them able to see all my DM notes hidden outside the map and has ruined a couple of dungeons now. Even if they are being honest, they can't unsee what they have seen. I have tried putting on the fog of war instead, but under the updated version it seems to be either FoW or dynamic lighting, meaning all the other players lose out on the DL also and I have to go back to revealing areas bit by bit. Tried explorer mode but seems that takes even more computing power than DL so not sure if that's a feasible option? 

Make sure that: They are using a supported browser (Firefox,Chrome) Their browser can run WebGL. They can test whether it works by  clicking this link .

Thanks Keith Curtis, they are using chrome and I have asked them to check the WebGL link after seeing some pointers on the website. I have also asked them to check their hardware accelerator and done what I can from my end as the DM by removing any circles and limiting DL to only that which is necessary, removing sight from any NPCs etc as suggested in the tips and tricks section of the roll20 website. 

On the dynamic lighting tab of both pages and tokens, scroll all the way down.  There is a Legacy Dynamic Lighting setting you can then toggle on.  This toggle needs to be constantly done everytime you go to a new page and all the player tokens need to have them setup and then saved as default.  Once you have legacy on, your life will be soooooooo much simpler.  Legacy lighting does not get blocked by adblockers and antivirus.  What your player is experiencing is actually a major flaw in their design as it allows any traditional adblocker/antivirus behave as a fog of war hack.   I suggest you always run with legacy dynamic lighting.  And yes, having to scroll down and do all that extra clicking is annoying.  It was not always like that, infact they had it up at the top in its own tab, but the devs who made UDL got jealous or something and decided to block it behind a ton of additional unnecessary clicks to spite their paying customers.  

I'll give at a try and report back. Thanks DM Eddie. 

DM Eddie said: On the dynamic lighting tab of both pages and tokens, scroll all the way down.  There is a Legacy Dynamic Lighting setting you can then toggle on.  This toggle needs to be constantly done everytime you go to a new page and all the player tokens need to have them setup and then saved as default.  Once you have legacy on, your life will be soooooooo much simpler.  Legacy lighting does not get blocked by adblockers and antivirus.  What your player is experiencing is actually a major flaw in their design as it allows any traditional adblocker/antivirus behave as a fog of war hack.   I suggest you always run with legacy dynamic lighting.  And yes, having to scroll down and do all that extra clicking is annoying.  It was not always like that, infact they had it up at the top in its own tab, but the devs who made UDL got jealous or something and decided to block it behind a ton of additional unnecessary clicks to spite their paying customers.   Hello. The suggestion by DM Eddie above has worked for my player so I can at least keep my game running by converting the remaining maps/other players onto the legacy system.  I know you said the new UDL is seen like a virus and therefore blocked by a lot of systems, I presume there is a way to stop this and to allow that particular program through the anti virus? Just I don't want to find myself in future unable to make use of one of the features I've paid for when the legacy lighting is eventually fully retired. Either that or is the antivirus issue part of development with UDL so it isnt an issue in future?  Either way, thanks for getting my game back on track for now. 👍🏼 

They will never delete LDL.  They would lose so many subs.  

So, now that a sunset date has been set for LDL. Have the bugs been resolved which were causing these issues with UDL or is my game likely to stop working again come May? :o(

Did I miss an announcement? When was a date announced?

There was an announcement for May of last year, but that didn't happen. I can't find anything on Blog, Twitter or Forum announcements.

Ah, you could be right. The announcement is dated Feb 21, but weirdly has only just come up on my account so i didnt think to check dates

Yeah, there's no year on the date in that post. But it's from 2021. No new Sunset date has been announced. Just, AFAIK, a cessation of development and support.