Dynamic Lighting fails intermittently when scrolling

Hi. I was a player in a game a couple of days ago, using dynamic lighting correctly (windows 7 pro, latest chrome), most of the map correctly obscured. Then, while I was using the right hand (vertical) scrolling bar, the whole map suddenly appeared with full brightness.  Then as I scrolled further it started and stopped working again.  When the GM started manipulating tokens it started working and not working as well.  Not good. Secondarily - perhaps unrelated - I do seem to get a lot more WebGL errors than I used to both as player and GM.  Is there any way to stop these (a reload generally seems advisable at the time) does something need to be updated at my end? Thanks.

Hello Sredni. Thanks for the heads up but can you supply a console log when it happens and to cover all the bases lets go with the complete troubleshooting guide. Can you please follow Steps 1-3 of our Solving Technical Issues wiki page, taking special care to temporarily disable all browser add-ons and extensions, temporarily pause your anti-virus, and try switching browsers (for Chrome/Firefox specific issues) to see if one of those components is causing the problem. If all of that fails, please follow Step 4 , including providing all of the necessary information, so that we can further assist you.

I'll try to do that next time it happens.  But as a GM, it's disappointing to go to the trouble of concealing most of the map if players can randomly see the whole thing.  Is it possible that the default is that players see a blank screen rather than the whole map?

Many GM's use what is called a splash page. It is a page that players ribbon sits on between sessions so that no one can come into the campaign board and peek around. Another trick that some GM's use is to activate the Fog of War to black out the map till they are ready to use the map. I would still recommend running through the troubleshooting guide and help us get some info (a complete copy of the console log) of what is happening. Do you know if it is only happening to you or is it happening to others in the group also? That might help us to know if it is located on your end or if it is more roll20 side.