This is because that this external drive is connected to the Mac computer through USB cable, USB port and many other components. What makes the hard drive not working problems like USB flash drive unmounted on Mac can be various.

Why the USB flash drive is not mounting on Mac? But don't worry, this page talks about the reasons for this issue, and how to fix 'USB flash drive not mounting on Mac' without data loss even if the external hard drive is not showing up on Mac. However, if the USB flash drive is not mounted on Mac, you will lose access to the USB flash drive as well as to the data stored on it. It is user-friendly that Mac will automatically mount the inserted USB flash drives. How can I fix/repair the USB flash drive not mounting issue on Mac? But the USB flash drive was grayed out in Disk Utility and I could not mount it. So, I went to Disk Utility, it was there. When I plugged in my USB flash drive on macOS High Sierra, I can't see it in Finder or on the Desktop. How to recover lost data from unmounted/unrecognizable USB flash drives? How to fix/repair USB flash drive not mounting issue on Mac? Please visit the Downloads page to find a version of the USB Overdrive that works on your system.Various fixes and updates for minor issues in 4.0.Improved support for Logitech Bluetooth mouse devices.New separate Line and Pixel speeds for Accelerated scrolling.Works with Bluetooth Smart (aka Bluetooth LE) devices.Installation instructions New in version 4.0.1: It works with USB and Bluetooth mice, keyboards, trackballs, trackpads, joysticks, gamepads and gaming devices from almost any vendor. The previous release of the USB Overdrive works great in macOS 10.15 Catalina and still supports macOS 10.14 Mojave, macOS 10.13 High Sierra, macOS 10.12 Sierra and 10.11 El Capitan. USB Overdrive 4.0.1 is available for macOS 10 Catalina. macOS Monterey 12.x or macOS Big Sur 11.1 to 11.6.x.Fixes a minor issue at device disconnect, restart or logout.Fixes a rare issue with Microsoft mouse detection.Shameless plug: My famous Contact Tool for iOS is back! New in version 5.1: Apple devices have custom support in macOS and they would lose functionality if taken over by the USB Overdrive. Note that the USB Overdrive does not handle any Apple mouse, trackpad or keyboard. I am still working with Apple to improve the scrolling experience. Please read the notes carefully and uninstall any previous version of the USB Overdrive before installing this one. The USB Overdrive works fine in macOS Monterey 12.x and Big Sur 11.1 to 11.6.x. USB Overdrive 5.1 is fully compatible with Monterey.

How to access usb drive on mac catalina