When browsing my Downloads folder, or any folder in general, on Windows 10 I have experienced the Working on it… message and it takes a few seconds to load. This doesn’t matter if I have a lot of files/folders or just a few, it still hangs.
Resolution
Open Folder Options > Set Open File Explorer to This PC. Try WinKey + E now.
If it opens fine, then problem is with Quick access cache, which can be cleared by deleting *.automaticDestinations-ms from the following directory, using Command Prompt.
del %AppData%\Microsoft\Windows\Recent\AutomaticDestinations\*.automaticDestinations-ms