If you are running MacOS 10.6.8 and higher and see an error message that this OS is not supported when downloading the app using Safari, Chrome or IE, please check your user agent setting using http://whatsmyuseragent.com/
If your Your User Agent is showing: Mozilla/5.0 (000000000; 00000 000 00 0 0000; 0000000), then some bot or anonymizer running on your computer is "masking your user agent."
For example, your Intego antivirus software is set to hide information. Please turn it off. And try to install the zoom.us app again.