USB Logitech Unified Mouse/Keyboard Quit Working

I had a Logitech Unified USB wireless mouse/keyboard combo that worked plug & play on Ubuntu 16.04.  While cleaning the PC I broke the Unified USB dongle (don't ask).  A new Unified dongle was $15 alone or you could get a new M510 Mouse and dongle for $20.  I figured, why not get the mouse too.  Once I plugged in the Logitech Unified Dongle, the mouse worked great, but there are no hardware buttons for pairing my old keyboard (k360 model).  A quick search online and I found the pairing software for Mac, Windows, and Chrome but not Linux. 

I had a plan I thought might work, I have a virtual windows 10 running on the Ubuntu 16.04 box so I downloaded the pairing software for windows and installed it on my virtual box win 10.  I then associated a USB port with the virtual win 10 and ran the pairing software on the virtual.  I plugged in the Unified Dongle when instructed and amazingly it worked and the k360 keyboard paired with the new Unified Dongle.  I then accidentally hit the RESET switch on the computer and it shut down while the virtual was still running.  Upon reboot I was getting no response from the mouse or keyboard.  In addition no USB keyboard or mouse would work (no input devices at all).  I could get into bios and the keyboards and mice worked fine, but once Ubuntu booted I could not type my password or move the mouse cursor.

How I fixed it;  

1.  After several resets I found the f12 key would bring up the GRUB menu in which I selected the ADVANCED option.

2.  This will bring up a 2nd menu.  I picked the 2nd option down the (upstart) one.

3.  This will drop you to a command line (Terminal) screen.  It will ask for your User Name and Pass Word.  Once you supply those you will be able to type commands.

4.  I reinstalled the xserver-xorg-input software from this command line with the following three commands;

sudo apt-get update

sudo apt-get install --reinstall xserver-xorg-input-all

sudo reboot

That was it.  After doing this everything worked just fine and the keyboard was still paired with the new Unified Dongle.

NOTE:  After doing this the hard way I've read that there is Linux software that does the pairing and more.  I did not use this software so you may want to research it before trying it but to install it you simple open a Terminal Window (command prompt) and type the following three commands;

sudo apt-get update   

sudo apt-get install solaar 

sudo reboot

After the reboot you will see a new icon on the top right of your screen near the date and time.

It's the bluish * looking one.

Here is an article about Solaar.  Good luck.