i have the same problem!!
* I downloaded emcc direct from my desktop creative cloud !
Same problem, from Creative Cloud app installed 8 newest versions of applications, none of them are showing in Extension Manager.
No XManConfig.xml files in Configuration directories.
Are you running Creative Cloud 2015?
Extension Manager CC is not compatible with that revision. see link below:
You should use ExManCmd line tool to install extensions for CC2015.
Similar issue: CC2015, tried installing NKS5, first with ExMan. Put NKS5.zxp in the ExManCmd extracted folder in downloads. Opened the command window there, ran it, no feedback or anything. Don't know if it worked, but when I booted up photoshop, NKS5 was not present under extensions.
Next up, I tried using ZXPInstaller. Dragged the file onto the program and let it do its thing. It said NKS5 was installed, but as you might guess, it didn't show up under extensions. Next I tried opening it with the program, and even though it said it was installed, it was not.
Next I tried a method that might make Photoshop run badly (one instance was bad, another fine) was to manually install it by installing it in C:\Program Files (x86)\Common Files\Adobe\CEP\extensions. But when I looked there... there was already a NKS5 folder there. Huh.
I'm completely at a loss at what to do next. Everything that supposedly works does not.