The update is not downloaded. Hung at 0%. What to do?

Mac or Windows, and EXACTLY which version of the operating system?

Recent Mac AND Windows operating systems have been known to cause "odd" problems

Also, what are you installing... program name AND exact version number?

Please read https://forums.adobe.com/thread/1499014

-try some steps such as changing browsers and turning off your firewall

-also flush your browser cache so you are starting with a fresh browser

-check hosts file for blocked entries https://forums.adobe.com/thread/1912777

http://myleniumerrors.com/installation-and-licensing-problems/creative-cloud-error-codes-wip/

https://helpx.adobe.com/creative-cloud/kb/creative-cloud-desktop-application-failed.html

http://helpx.adobe.com/creative-cloud/kb/failed-install-creative-cloud-desktop.html