The Codebook installer does not correctly detect that Bonjour is already installed on a system (Windows 8.1), and tries to download and install an older version. The most recent iTunes comes with Bonjour 3.1.0.1, but the installer still tries to install Bonjour Print Services version 2. Canceling the install of bonjour and continuing with the install results in a fully functional Codebook install.
The installer should not try to downgrade Bonjour to an older version.