Thank you for your purchase! I am sorry to hear about the issues downloading and installing the TOOLS for UR-C. While I wasn’t able to reproduce this here or at home, let’s try a slightly different file (.pkg instead of .zip): http://download.steinberg.net/downloads_hardware/UR-C/TOOLS_for_UR-C_V1.0.1.pkg
Also, please note that today, we have released a new Yamaha Steinberg USB driver V2.0.2. It should be installed if the TOOLS installation could be completed successfully now. You can find it on this page: Yamaha Steinberg USB Driver Updates and Downloads | Steinberg