Zoom Screen Sharing freezing on MacOS

You're all set. You've got the best presentation ready. Your green screen is shiny and your new pinstripe T-Shirt displaying the M1X logo on the chest is well pressed and lightly starched and you're totally killing it on your 4K webcam, but then one of your participants says, "Oh?  Did you change slides? Your screen sharing is frozen."  

OK.  So you close the sharing and turn it on again and it goes even worse: "Now it's a blank screen."

A NIGHTMARE! And you KNOW your hard wired connection to gigabit ethernet can't be the problem. And they say your are looking GOOD on the webcam. That means this is a screen sharing problem.

Here are some things that worked for me if you're living this nightmare:

Of the following two steps, doing the steps in #1 didn't resolve the issue.  Doing the steps for #2 did.

1. learn about your Mac's ability to switch video card, know how to identify what card it's using, and configure it to not switch when connected to power.
2. configure Zoom to avoid the situation

I included the steps of #1 because:

• sometimes more knowledge will save your bacon, 
• I wanted to capture these notes, and 
• if you're a live streamer like me (TDD.Academy Youtube, TDD.Academy Twitch), you may need to "amp things up" to increase your frame rates for your live stream.

It's possible after some time and experience, that I'll go back to #1 and allow my machine to automatically switch video chips while connected to power.  But for now, I've some experiments to try out.

Did you know your Mac could have more than one graphics processor?

Go to your battery settings to see if your Mac has "Automatic graphics switching." If it does, you've got more than one graphics processor.  Here are the steps:

For more background, read this article: https://it.umn.edu/services-technologies/how-tos/zoom-black-screen-during-screen-sharing

If you're curious about which GPU your machine is using at any time, either open Activity Monitor or click on the apple icon in the menu bar and select "About this mac."  Activity Monitor will tell you if they are using the "high performance" card or not.  About this mac will tell you which GPU (Graphics Processing Unit) is active. Typically the low power GPU is from Intel and the high performance one is from Radeon or Invidea.

To change or turn off the ability to switch GPUs, your can deselect the "Automatic graphics switching." I did this for when my machine is running on power.  I want it to select to the low power GPU when it's running on battery.  When I'm presenting my best face to the world, I'm usually connect to battery and hardwired to the LAN.

Zoom settings that solved this problem

Zoom has two interesting settings.  One of which, I'm sure resolved my problem.  Go into Zoom preferences and turn them both on if your having issues.