In case a black screen is shown as above, follow the steps below.
1) It is necessary to check the memory status of the PC. Please close any programs you are not using.
2) Check whether the internal firewall is set to allowed on RemoteMeeting service.
Link: Firewall information
3) The camera may be blocked by security application. Check camera settings
4) Re-enter the meeting by refreshing (press F5).
If the problem persists, contact us via Helpdesk.