I tried a bunch of options, but nothing seems to work.
I can't install any Adobe Add On on my Macbook.
When I visit the adobe-my_addons page,
I can choose Add Ons and install them, but nothing happens.
So I tried to remove and install them again - nothing at all.
I tried it with another browser, with another version of Photoshop.
Tried it with Add Ons for other applications like After Effects or Premiere Pro,
closed the programs, started them again - still nothing.
I also uninstalled Photoshop to install it again....
or to work with the Adobe Extension Manager.
I have no idea, what I could do or where the problem is.