I hadn't updated Foobar2K since 1.6.2. When I checked for an updated version from within the program, it gave the message, "Update check failure: Network authentication error (80090302)".
So I went directly to the website, downloaded and installed 1.6.6. Program still gives the same message, and similar messages for Updated Components and Online Troubleshooter.
In the past, these links within the program had always worked. Computer runs Windows 7, no proxy server, nothing recently changed. I installed a new router several months ago, but that hadn't caused issues with any other program.
So where to look? I'm not ultra-techie like a lot of folks here, but follow directions well. :D
https://hydrogenaud.io/index.php?topic=118821.msg980059#msg980059 (https://hydrogenaud.io/index.php?topic=118821.msg980059#msg980059)
Thanks, Sveakul. Worked like a champ.
I swear that I searched the forum before posting -- but I searched for "error (80090302)" -- and the fix was posted under "error (80090326)." Oh, well.