premiere pro wont install - mac

First off, how old is your Mac? If it does not meet the new requirements for the current version (e.g. your hardware must not be more than three years old at the time of the major version's release), or if your currently installed version of OSX is outdated, the individual CC apps will simply refuse to download and install, with no warning or error message at all whatsoever. This hanging will be permanent. (This can also happen if the version that is compatible with such older hardware or an older OS is now no longer available at all from Adobe, which is now restricting availability to the two most recent major versions.) The only way to break the download connection, under this circumstance, would be to hard-reboot your Mac.

Future versions of the Creative Cloud desktop app should flag the individual CC apps as "Not compatible."