Hello,
i’ve deployed Openvidu on my Linux server (Ubuntu 16.04) connection is fine and i can join calls on the main page at https//mylocalIP between multiple pcs.
Now i’ve installed the classroom demo at port 5000 and are able to log in just fine.
The problems i have are: if i log as teacher and start a lesson all i see is the gray bar on the top screen with lesson name and mic/camera/fullscreen option. but there is only a white background and no camera feed.
Also students account seems to log on a different istance of the server since thay cant join calls even if i’m connected as a teacher inside (receiving “teacher not started yet” error) and also can’t see new lessons ( but if i create a new lesson as teacher from a pc than connect with the same teacher account from another i can see my new lesson)
Thanks for any help, im not quite familiar whit server sided tech 
EDIT:
after some research i’ve found this error when i join a session as a teacher
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