I have downloaded the latest version (3.0.86137). (Had the same problem with an older installation of Version 2)
When I try to authorize the computer, I get the error message E_AUTH_NOT_READY When I click an Open Library link, I get E_ACT_NOT_READY
I have a 2013 MacBook Air running Mavericks. (Had the same problem before installing Mavericks. Just getting to try to fix it now.)