Microsoft Teams - Black screen when sharing desktop, works with single application

Hello Treawlony1986,

Thanks for your post in Microsoft community. Since you are able to share your screen as single application in Teams desktop, so first of all we suggest you to kindly double verify you have assigned Meeting policy with entire screen sharing mode.

For this:

1. Login with Microsoft Teams Admin center : Users > Search for your user account > check Meeting policy name assigned to you
2. Now Go to Meetings > Meeting policy > search for the meeting policy which was assigned to you and click on edit option to view all settings > go to Content sharing > check screen sharing mode is set as “Entire screen”.

Further based on your post, could you please kindly let us know, when issue occurred, is there any activity performed on your system (such as update Windows, Teams and any other such kind of activity)?

• Kindly share us screenshot or video about your issue, it helps us to identify issue more clearly.
• To narrow down this issue, we request you to kindly run Teams Debug logs and share us the result.

Kindly share above request information via the Private Message.  For your privacy, we will send it to collect further information.

Thanks and regards,

Ankita Vaidya

Hi Ankita,

I will run the debug, permission to share the screens are ok.

I just noticed something else: currently I'm connected with my surface laptop on my 21:9 widescreen monitor, lid closed (with Surface Dock).

Opening the lid, laptop screen get shared, but still nothing on secondary monitor.

then I tested the following:

• Sharing an application was working fine
• I've opened the application full-screen, shared the application and got black screen again
• I've then shared a windowed application and expanded to full screen, and was working fine.

Looks like somehow Teams is not able to digest anymore a full-sized screen sharing from a 21:9 monitor (thing that it was able to do since couple days ago).

Just checking windows update, closest update i've got (not considering windows defender) was on the 13 of FEbruary the security update KB4524244. But it was working fine those days.

Hello Treawlony1986,

Thanks for providing brief information. To narrow the issue, we request you to kindly provide us further below information.

• Screenshot or video about your issue.
• Teams version information details screenshot. For this : Click on your profile pic in Teams > About > version
• Kindly run Teams media log and share us the result. To run that logs, please check Teams Media logs.

Kindly share above requested information via the Private Message.

Thanks and regards,

Ankita Vaidya

Hi Ankita, will send you shortly.

I do not any screenshot or video to share as it's the other side that see the screen black

Hello Treawlony1986,

Many thanks for your Time and patience. We had received your private message and our consult team had checked the logs but not able to found error message for this issue. We had also observed that your Teams version is old. The current teams version is 1.3.00.3564 (64-bit). It was last updated on 2/27/20. So first of all we would like to suggest you to kindly update your Teams with latest version and check the result. If still issue persist in latest Teams version, it might be some backend issue. For that our consult team suggested for next action plan and we will send you it via the Private Message.

Kindly check Private message.

Thanks and regards,

Ankita Vaidya