Ideally, use the AC adapter kit ACK-E4 to power supply your camera while connecting to the computer. Finally, check if the error has been fixed or not. Next, connect your camera to your PC using a USB cable and turn it on. Plug in the power cord of your PC and restart it. Shut off your device and wait for a few minutes before turning it on. So, before applying longer solutions, restart your Canon camera and your PC. Sometimes the issue can be as small as restarting your devices. So, let’s take a look at the possible fixes: Restart Your Computer and Camera Some of these solutions apply to both Windows and MAC won't recognize camera USB issues. If you’re using a Windows computer, then the following solutions can help. How to Fix Canon Camera Not Showing on PC? It helps avoid issues like the external camera not showing up on MAC. So, as and when you are updating your operating system, make sure you also install the updated or the latest USB driver kit. Updating USB drivers help fix many system-related issues and bugs. Otherwise, the USB port won’t be able to recognize any connected device, including your Canon camera.
In the context of connecting with your Canon camera, you've to make sure that the external USB on your system is updated. As your Windows or macOS advances, you need to update associated drivers as well.