Source
r/MicrosoftTeams•
fuzzball007

Black screen on any outbound video transmission

Question/Help

Got a headscratcher of an issue that I haven't been able to solve. All outbound video transmission from me (screenshare, camera) appears as a black screen for others, but on my end shows up as normal and as though my cam/screen is being shared.

Specs:

  • Windows 10 Pro (1909 / 18363.959)
  • Teams Desktop App (latest version)
  • Nvidia GTX 970 (if that matters at all)

Other things I know/have done:

  • Firewall on/off makes no difference
  • Appears to be no increased network traffic when cam is on, though I did this while in a solo call so might not attempt transmission until someone joins
  • No IP addresses blocked in hosts file
  • No unusual/custom firewall rules present which could block
  • Network isn't the issue - tethering teams off my phone (which uses data rather than wifi) still doesn't show any video. Used Teams on my phone and had no issues.
  • Ran one of Microsoft's tools for checking ports related to Teams/Skype for Business, didn't mention any errors/block when completed
  • I've got multiple virtual machines (one through VirtualBox, other through WSL) and servers of sorts (Node JS) running which might take/block ports
  • "Allow desktop apps to access your camera" is turned on (with Microsoft Teams showing in the list)
  • Zoom and Discord (native desktop apps) both work fine and have no issues with video
  • Years ago I made various rules to block Skype ads (likely through hosts file) which did cause some other issues for some other Windows/Microsoft bits (Weather widget in start menu didn't auto update after change)

My guess is that it's a port blocking issue, but I've got no idea how to unblock it let alone how to check it, any help much appreciated.

Posted Aug 5, 2020, 9:31 AM UTC · edited

03
SnooRobots1033•

Did you find a fix for this problem?

1
fuzzball007OP•

Nup, gave up and just told clients/coworkers that I couldn't share screen/cam and to use something else when they needed to see something from my end. Still convinced its something on my machine blocking outbound video, but not worth the time investment to find out anymore

1
nn-red•

According to few minutes of investigation, this seems to be a bug in Teams (possibly incompatibility with something). So if camera video works in Zoom but not in Teams desktop version, try this: when you open a meeting link, close the desktop version. Instead, in the forwarding page choose to use the browser version. Now the camera might work.

You can also go to https://teams.microsoft.com/ for the browser version, and you should be able to make video calls etc. from that version, camera should work even it's black in the desktop version.

1