1) Make sure the user signed in is a LOCAL OR DOMAIN ADMIN as the user might not have rights to download or install.
2) Your company may be blocking access to the Amazon Cloud, where the files are stored. Contact your IT team to get assistance.
If you are running an older version, or you find there's trouble installing anyway - our ON PREMISE customers will be able to access an Offline Installer through their Docstar/Eclipse Servers. Here is how you access the Offline Installer.