How to disable the block editor from managing widgets?

A recent version of WordPress brought block editors to widgets. Certain plugins like Advanced Business Hours and Advanced Music Widget are not compatible with the block editor.

Simply download Classic Widgets plugin: https://wordpress.org/plugins/classic-widgets/

Once activated, this plugin restores the previous widgets settings screens and disables the block editor from managing widgets. There is no other configuration, the classic widgets settings screens are enabled or disabled by either enabling or disabling this plugin.