Software developers are coding Microsoft Edge Webview2 into their applications & not explicitly informing end users that need this component installed & working to avoid error pop-ups, see missing content and, have full access to all functions of the app.

For those of us that have disabled/uninstalled the Edge Web browser and/or off-line systems, the following article should help.

Microsoft Edge WebView2 Runtime Silent Install (How-To Guide)

For some reason Microsoft has made it more difficult to install downloaded cab files to do updates.
Normally you could run DISM in an Command Prompt as administrator. This is no longer 100% viable.

One workaround is to find regular installers from the Microsoft Developers site.