What troubleshooting steps can I take to resolve the Canon 70D ERR 20 error message on my camera?

To resolve the Canon 70D ERR 20 error message on your camera, you can try the following troubleshooting steps:

1. Turn off the camera and remove the battery for a few minutes, then reinsert it and turn the camera back on.
2. Check the lens and make sure it is securely attached to the camera body.
3. Clean the lens contacts on both the lens and the camera body with a soft, dry cloth.
4. Update the camera firmware to the latest version available on the Canon website.
5. If the error persists, contact Canon customer support for further assistance.