I intermittently get errors updating the library. Just keep trying and it eventually will go. Sometimes only a couple of attempts will do it, sometimes it takes 8 or 9 or more. This has been a problem for some of us for a long time now. I think it has to do with my Verizon wireless access, it seems like it was discussed last year (or earlier?) and a common denominator of Verizon emerged. Or I may be mistaken. I don't know who your provider is but that could possibly be a factor.
Bottom line, when you've whitelisted and taken the other advice above and it still errors out, just keep hitting it, it will probably eventually update.