Thanks for finally getting back to me with an INCORRECT and INADEQUATE ANSWER 48 hours after ADOBE's problem manifested itself. I followed the directions and tried to use the offline installer more than 5 times. Along with clearing caches, emptying the trash, uninstalling the old version, shutting down, waiting 5 to 10 minutes before powering up, and going through the whole install process more than 5 times I finally called APPLE and the CSR there was able to help me get it up and running. Apparently ADOBE's problem with this update and its installer is widespread enough that APPLE had its CSRs learn how to fix the problem. ADOBE needs to do a better job of final testing. Turns out this time the software and its installer were released with inadequate testing and although the software was fine, the installer was worse than useless. But that's ok, APPLE was able to fix ADOBE's problem. The next time an ADOBE app gets updated I will wait a few weeks and read a few more reviews before installing. If I decide to use the update.
I have over 15 years experience with a home iMac and this is a brand new computer and is not the first time the installation of an ADOBE product or upgrade has been problematic. The software and updates work great when they finally get installed, but installation is a pain enough to want to try something else.