Canon's EOS Utility Beta allows you to use a Canon DSLR cameras as a webcam on your Mac, but it can sometimes cause Ecamm to crash.
Please note that using the EOS Utility Beta is completely different from, and can interfere with, using Ecamm's built-in ability use a DSLR cameras as a camera.
If you see EOS Webcam Utility Beta in the Camera menu in Ecamm Live, then these instructions apply to you.
Here's how to uninstall Canon's webcam plug-in so it won't interfere with Ecamm. This won't have any affect on EOS Utility other than to disable the webcam functionality.
Go to the Finder.
From the Go menu on the menubar, choose Computer.
Navigate to the folders: Library ➟ CoreMediaIO ➟ Plug-Ins ➟ DAL
Find the file called EOSWebcam.plugin
5. Drag this plug-in to the Trash, or pick Move to Trash for the File menu.
6. You will be prompted to enter your computer password or fingerprint.