Android System WebView -or WebView of the Android System, in Spanish- is an application that comes with Android and that allows other applications to display web content directly in the application, without the need for everything to open in a new tab in the browser .
It is a very useful system by which an application like Gmail allows you to open links in an email directly in the application itself, without changing to the browser. These applications are precisely the ones that are failing now, as they are closed when trying to use the system's WebView. It would be impossible to make a complete list of all affected applications, but users mention some such as Gmail, Outlook, Google and Paypal, although it should affect many more applications.
This error does not seem to be affecting all Android phones, but it is probably the combination of several factors together with the latest version of WebView on the system. If you do not have problems in the present, it is best that you leave everything as it is.