Updating to WordPress 5.8 breaks the widget page, it displays as a white page with the following error:
TypeError: Cannot read property 'PluginSidebarMoreMenuItem' of undefined
at react-dom.min.js?ver=16.13.1:175
and a second: Uncaught TypeError: Cannot read property 'PluginSidebarMoreMenuItem' of undefined
react-dom.min.js?ver=16.13.1:161
The error goes away and the page loads correctly if Views is disabled.
I know that Views is a legacy plugin, but i do have a large number of sites that depend on it, so if we could resolve this error for WP 5.8 that would be huge.