Meaning of Download Authorization, value 401?

Looking at the Remote Administration Console for NOD32 2.7, on the Event Log tab, a number of our client computers are showing an event with Function DownloadAuthorization and a return value of 401.

What does this mean, and what, if anything, should I be doing to correct it?

Also, there are a number of other events shown there that I don't understand. Rather than asking about every one of them here, where can I find documentation of the meanings of all of them?

Thanks.

(I first posted this in a different forum, and now can't figure out how to delete it from there. Sorry about the duplicate.)

 

Here is the list;

http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

401 is not authorized. You probably have your HTTP server, be it the RA mirror or something else, set with authentication (user and or password) while you don't have your clients defined to authenticate. My guess.