Well - in case I hadn't read it earlier (which I did) thankfully you posted it in capital letters 20+ times. I already tried that and it didn't work. This is what I have done so far to try to get it to work.
1) I modified the permissions to all groups (using the steps outlined in a prior post) to allow updating to all files within the Program Files/ World of Warcraft directory
2) When I was still getting the same error, I moved wow to another directory (not in Program files) - as was suggested in a prior post and modified the permissions to the new folder such that all groups had access in the new folder to modify all files
3) When that didn't work, I turned off UAC thinking perhaps that would help. It didn't.
I was still getting the same error.
I looked for another option of installer and found something else listing Java as a dependency (having a completely new software install, I did not have Java installed). After installing Java the regular WoW Ace Updater works. Does the WoW Ace Updater use Java? Nothing else changed between when the program didn't work and when it did.