My command center and Service center are both identical 523.2 mb
Downloading now.
UPDATE: I get the same thing as you J "download is not possible" Sheesh!

I'm running Service Center version 2.6.0.137, and it downloads Kontakt 5.6.1 OK, but install fails:
 
"Installation is not possible since the full version of Kontakt 5 is found on this computer. The latest version of Kontakt 5 can load all Kontakt player libraries. You can update your existing Kontakt 5 full installation by running the latest Kontakt 5 update installer!"
 
I don't get it. I've been keeping it up to date. The latest was September 12, 2016. When I run Kontakt, the about box says Version 5.6.0 (R46).

I ran the latest update and I'm not a happy camper.  First, my Kontakt GUI was changed, and there is no large font anymore...it is very hard to read, and the modules in the instrument rack are small.  The window will not resize up anymore (will not get wide).  THEN, my DLL files were not installed ANYWHERE on my computer!  WTF?  I had the old Kontakt.dll files on a storage drive and placed them in my Vstplugins folder, but apparently Sonar doesn't recognize them since the update.
So I have emailed NI support and waiting on an answer.
Tick tock, tick tock.....

Yeah - it seems like Native Access is installing with neither "AAX" or "VST" selected  - how clever!
I noticed this when I installed the update manually (after pinching the Native Access download file before it deleted it)
These choices must be stored in the registry somewhere - but why you would automate an installation that doesn't select anything is beyond me.

OK. Took the Native Access plunge at last. Nice.

This might not be relevant to some of the problems talked about here, but it's a follow-up to my post from yesterday about the install failure.
 
Today I opened Service Center, and there was a new 5.6.1 update for Kontakt -- 160MB this time instead of 510MB yesterday. I clicked Download and then Install, and it installed successfully. Apparently NI had uploaded the wrong file and fixed it the next day.

All of my NI installs fail until I use the Windows Installer Cleanup Utility.  I've had that bug since Komplete 6.

Still don't like K 5.6.1 ... it takes ages to load libraries and still blocks Sonar completely while loading ...

Anyone else seeing this? Did some default settings change or is this the new version???

I'm still holding at 5.5.2 until I am forced to update.

dug out the link from the other thread and started downloading 5.5.2
 
https://www.native-instru...mp;refresh=ky6h12010ra
 
can I simply uninstall 5.6.1 and install that 5.5.2 installer? will it work with libraries and licensing?