Logitech MX Master Frequently Asked Questions Manual page 17

NOTE: If a feature still doesn't work after you grant access, please reboot the system.
 +USB receiver does not work or is not recognized
If your device stops responding, confirm that the USB receiver is working properly.
The steps below will help to identify if the issue is related to the USB receiver:
1. Open Device Manager and make sure your product is listed.
2. If the receiver is plugged into a USB hub or extender, try plugging it into a port directly on the
computer
3. Windows only — try a different USB port. If it makes a difference, try
USB chipset driver.
4. If the receiver is Unifying, identified by this logo,
device is found there.
5. If not, follow the steps to
6. Try using the receiver on a different computer.
7. If it's still not working on the second computer, check Device Manager to see if the device is
recognized.
If your product is still not recognized, the fault is most likely related to the USB receiver rather than the
keyboard or mouse.
 +Logitech Options black screen, stuck on scanning, or no detection of device
Symptom(s):

No device is found in Logitech Options homepage or the screen is all black

Logitech Options stuck while scanning with a spinning wheel
Possible solutions:
1. Check if your device works correctly within the operating system. For example, if you have a
mouse, does the pointer move on the desktop? For keyboards, can you type with your
keyboard?
o If you have Windows system, check to see if your device is found in Devices and
Printers. If you can't see your device, check
unrecognized devices (normally a yellow exclamation mark).
o
If you have Mac system, click on the Apple symbol – About this Mac – System Report –
on the Hardware tab look for USB. On the right side, you will see the USB device tree.
2. Check if .NET Framework is up to date. See the Microsoft instructions here.
3. Try to install Logitech Options while your computer is in a clean boot state (this is different from
booting into Safe Mode). When you perform a clean boot, Windows starts with a minimal set of
connect the device to a Unifying
updating the motherboard
open Unifying Software and check if the
receiver.
Device Manager for any errors or