I have installed vscode-icons extension. And set this as my preferred File-Icon Theme using File -> Preferences option in Visual Studio Code. All folders and files icons disappear. The extension is installed properly and I could see all the icons in the installed extension folder.
But when I switch back to Set(Visual Studio Code) theme, all the folder and file icons are visible. I have tried all possible options like install and uninstalling packages, libraries, extensions and VS Code itself. Please find below screen shot,
I am able to see folder and file icons after installing one more alternative extension called file-icons.file-icons.
Earlier I tried at least 2 extensions. But to my surprise, none of them worked. So I assumed that, something wrong in the VS Code.