Try updating or reinstalling the Adobe Desktop App and update from there.
I would try uninstalling Photoshop and the Creative Cloud desktop app. Then download and install the latest Creative Cloud Desktop app from here:
Hope you find this helpful,
Rather than reinstalling the Application Manager, I'd be inclined to first restart your computer, and run the Application Manager as Administrator by right clicking its icon. Then try updating again.
It looks like there was an issue with the Creative Cloud rather than Photoshop itself. After reinstalling it updated smoothly!