Thanks for the ideas. I tried both then cleared the paclet directory. There was no improvement. So I decided to find a Demonstration that used this type of data. After some searching, I found one that used AstronomicalData. The demo was hanging on initialization, so I downloaded the code. It brought up a flag/button that asked me to 'Enable Dynamic Loading' which I then did. Then came a flurry of messages relating to downloads from the Wolfram Research Server. Now everything is working as it should. I'm not quite clear on exactly how that fixed things (I'm pretty sure that the preference for allowing Dynamic Updates was set to true). Again, thanks for your help.

Thanks Sander,

That's what my preferences are set to (unfortunately). I tried the Test Connectivity button and got a successful response. Still no evaluation. Curious!