Thank you, Lowlander and CrashMonkey, for your suggestions and for taking the time to respond to this post.
I really didn't plan on spending a lot of time on this issue so I just reinstalled MM version 5.0.5.2695 and
Artwork Lookup is working fine again.

This can happen if MM is blocked in a firewall. The default windows firewall will allow the connections. If you have any 3th party firewall that could block it, if so check that.

Please capture this in a debug log (step 4b) and attach the log to a Support Ticket: viewtopic.php?t=86643

This will help a developer analyze why this happens on your setup.

While in MM, from the panel on the left (Media Tree?) I select the drive letter then folder that contains my music files. Then on the main panel (right) I right click on the file I want to tag and select Properties. Then in resulting window I have six options Basic, Details, Classification, Lyrics, Artwork and Custom. I select Artwork where you can then choose from two buttons Browse...or Lookup Image... I then select Lookup Image and the resulting window pops up blank with the word Searching... and a little circle twirling around next to it. That's it nothing happens. It eventually disappears, giving up I guess, and no artwork shows up. Any ideas to fix it would be appreciated.

Where exactly within MediaMonkey do you click for Artwork lookup? It's working here.

Is it possible to get the Artwork Lookup working again? It was working just fine on MM version 5.
But I made the mistake of upgrading to 2024.0.0.3082 and now it doesn't work. Click on Lookup Image... and it sits there
searching. I am using Windows 10. The previous fix for this problem does not work. Thanks.