Hi @DianeBigger,
As Zoom is a 3rd party integration with Canvas, it's going to be pretty hard to give a general answer for this. There are different Zoom integrations and a lot of options that can be set up for the integrations. I'd suggest reaching out to your school/institution Canvas and Zoom teams (usually in the eLearning / IT / Digital Education areas) and letting them know you're running into an error. Hopefully they can work together to fix the error or create a ticket with Zoom if necessary. My off the cuff guess as a Canvas admin is that there might be a permission that hasn't been set properly somewhere that's causing the process that lists all of your courses to fail, but there could easily be something else going on that your local teams can figure out.
Hope this helps, even though it's not an exact fix right now.
-Chris