trouble with Kontakt 5.6

I upgraded from Kontakt 5.4 to 5.6. The standalone contact is now 5.6 but the version within Sonar is the old one. Any hints?

I had the same problem - standalone updated, but DAW version did not.
I solved it by going back and forth between their 2 upgrade programs (Native Access and Control Center?) till finally their older program (Control Center) saw that it had not upgraded properly.  
Actually had this happen twice in a row... they have had 2 recent Kontakt upgrades.  Hope this helps you.

It's not the plugin manager's fault. It's just reporting the names that the plugins themselves return to it when it queries them during a scan. Fortunately, we are able to rename them ourselves, which is handy not only for Kontakt but all plugin families that start with the same word, e.g. FabFilter stuff.
 
The difficulty the OP was experiencing was that the NI installer was writing the updated DLLs to a location different from what he'd been using previously, resulting in duplicates.
 
The first time I noticed a version difference between SONAR projects and standalone Kontakt and realized why, I copied the newer versions into my preferred location. The problem with that solution is that I'll have to remember to do that each time I update Kontakt. With some other plugins (e.g. Melda) I just gave up trying to impose my will on them and let the installers stick 'em wherever they want. That's also an option for Kontakt: delete the old DLLs and add NI's preferred location to the scan folders list.

Cool. I had to rename them each time Sonar did a scan.

beware , this vesrions is way less solide that old one when it comes to perf specially voices .... be sure to compare , keep both veresions and compares heavy patches ...confirm even during a discussion i had with Spitfire guyz ...