I purchased Master Collection (CS) Perpetual in 2015. I was told to also purchase a Creative Cloud subscription.
I later learned that I did not need a CC subscription and cancelled it.
Now, I can’t open Illustrator & access my files.
Adobe tech support reloaded my Master Collection and told me it would solve the problem. It did not.
I was then told to uninstall CC completely and re-install the Master Collection. A pop up screen told me I could not uninstall CC because CC Applications on my computer require it. Also very worried I will lose my Illustrator files.
Read Cloud takes over https://forums.adobe.com/thread/2089127 for some ideas (see reply #1)
-includes information on how to stop the update manager and/or Cloud from running at startup
-above is for Windows, but may help with ideas for Mac