It sounds like the installer may not have proper rights in relation to a specific directory needed for installation. I'd try the update from a newly created account with admin rights to see if you get the same result.
Here are some docs explaining the process if needed:
Thanks Dave. I like to keep my computer very clean and simple. I don't want to mess things up by creating a new user account, but I appreciate the advice.
This is a new issue. I have one account and i am the admin, so there must be something to do with this particular update.
My current Adobe programs still work fine, so for the moment I don't need to update my Adobe apps. I will just not install the new CC update until i can find a solution, and hold off on getting the new adobe app updates.
Maybe Adobe will release a new update that fixes this issue without requiring me to create a new user account on my computer.
Testing in a new user account was simply a troubleshooting step to test if the issue was specific the user account you were using. The issue you're encountering isn't something I've heard of very many others reporting of, so may not be something that could/would be addressed by a future Adobe update. I'm not sure if this is a user account related restriction for sure, but the error message definitely pointed to it potentially being the cause.
This document might be helpful for you in giving a little background on user account specific issues: Troubleshoot unexpected behavior | User account-specific | Adobe software | Mac OS
Also, here is a similar doc from Apple: Isolating an issue by using another user account - Apple Support
Just an update - i reset my permissions mac wide at some point because i was having my mac restart into grey screen, and afterwards the installer worked. i don't know if that had anything to do with it, but im guessing it MIGHT have because restricted permissions were part of the error message from Adobe.