Hello there,
My webcam doesn’t work with Demiplane but works perfectly fine everywhere else (roll20, Discord) (but not Messenger for some reason…)
I have absolutely no idea why.
Also, nowhere is explained or demonstrated what actually IS a Nexus…
good job over all, the app looks sleek and minimalist, i love it
A.
Because Demiplane uses your webcam through your browser, it may be worth double checking your default browser settings there. In the past, we’ve seen restarting your computer also solve video issues.
However, should you go through and find that doesn’t resolve things for you, you’re welcome to submit a ticket here and we’ll look into it: https://support.demiplane.com/hc/en-us/requests/new
As for what a NEXUS is, here’s the short answer: A Nexus is a hub where many things connect, so we’ve created a Nexus for each game system that we support where the digital reader, rules compendium, and character tools (coming soonTM) all come together as resources to make your gaming experience easier. Players and GMs alike can use the digital tools that we’ve created to make gameplay as seamless as possible. 
whitelisted camera, used incognito mode, check webcam drivers… nothing worked… my webcam works fine with Discord and roll20 (but not with Facebook no idea why either)…
anyway I’ll survive… but that will keep me away from using demiplane VTT
PEACE
One simple check that you might have already done is to make sure you haven’t erroneously made the specific domain unable to use the webcam. I use firefox, but I think they are all pretty similar in that you should be able to click somewhere to the left of the url bar and it will show you what permissions are enabled / disabled for that specific site.