Overview
When you are sharing a screen with a colleague, you may experience a black screen. In this case, you will need to follow these steps to help you resolve the problem.
- This is a known issue. Apple is working toward a solution to resolve the issue if you are experiencing this issue on MacOS Big Sur. In the meantime, we recommend switching to a wireless connection or changing the connection settings in your network interface to TCP until the problem has been resolved.
- The following troubleshooting steps will help you find out what is causing your monitor to flicker when you are screen sharing. If you are on a Windows device, follow the troubleshooting steps for screen flicker when screen sharing.
Windows
This may occur when you are sharing your screens with a graphics card that automatically switches graphics modes (for example, when you are using an Nvidia card).
- If this happens, you can access the Nvidia Control Panel through the Control Panel in Windows.
- Simply click the Manage 3D Settings button.
- If you want to choose the following 3D settings, click on Program Settings under I wish to use the following 3D settings.
- The Zoom bin directory contains the Cpthost.exe file which can be found under Select a program to customize.
- You will be able to see the file under Add.
- You will be able to find Cpthost.exe in the Zoom bin directory (located at C:/>Users>YOURUSERNAME>AppData>Roaming>Zoom>bin).
- Then, select the program that you want to use.
- On the previous page, select Integrated graphics from the Preferred Graphics Processor drop-down list.
- Selecting Apply will complete the process.
- Zoom screen sharing should now be working properly.
Linux
users will be unable to share screens due to compositing issues. Installing the XCompMgr3 third-party compositor is as easy as following these instructions.
Installing xcompmgr
Install xcompmgr using the package manager in your Linux distribution. You can search for xcompmgr in your package manager (such as Synaptics or Synaptic) if you have a graphical package manager.
You may also be able to initiate the relevant command from the terminal on your Linux distribution:
Debian, Ubuntu, or Linux Mint
sudo apt install xcompmgr
openSUSE
zypper install xcompmgr
Fedora
dnf install xcompmgr
Arch Linux
Instructions can be found in the Arch Linux wiki.
Configuring xcompmgr
Once you have installed it, you should open the terminal and type:
xcompmgr -c -l0 -t0 -r0 -o.00
Zoom Help 
Rahul Gupta