Well, I seem to have fixed the problem. I opened the Control Panel, selected Programs > Uninstall a program, selected Dell Update for Windows 10, selected Repair, and now it works fine. The Installed On date is now 08/10/20 (today). Interestingly, the Version number is shown as 3.0.0 in the Installed Programs list, whereas it is shown as 3.1.3 in the application.    
I recently updated the Dell Update Application on my Dell Inspiron 3670 desktop PC, and now when I run it and click on CHECK it hangs with the Warning: An operation is currently in progress. Please wait until it completes.The progress bar is stuck on "Operation is 40% completed..." I've tried restarting my computer several times, butit still does this. Is there some way to repair or remove/reinstall this application to fix it ?
Dell Update Application broken