Fixing "Your device is missing important security and quality fixes."
Refer: https://www.youtube.com/watch?v=1wjtBFTPR00
On a Windows 10 based computer, the following warning message is displayed in Update and Security center: "We couldn't connect to the update service. Your device is at risk because it's out of date and missing important security and quality updates. Let’s get you back on track so Windows can run more securely."
Telemetry Level: There is an option in Windows Group Policy Editor that allows you to control the levels of the Telemetry. It just so happens that some Windows Updates (especially the cumulative updates) won’t be delivered to your system if your Telemetry level is set to Security only.
This tutorial will apply for computers, laptops, desktops,and tablets running the Windows 10 operating system (Professional, Enterprise, Education) from all supported hardware manufactures, like Dell, HP, Acer, Asus, Toshiba,Lenovo, and Samsung).
Here's the fix
gpedit.msc
"Computer Configuration"
"Administrative Templates"
"Windows Components"
"Data Collection and Preview Builds"
"Allow Telemetry"
Originally "Not Configured"
Changing to:
Enabled, Enhanced