This thread by @Jeremy_NI here:
…provides tips to reestablish integration between Logic Pro and Komplete Kontrol MK3 keyboards. This new version of an old problem started to occur for me after Komplete Kontrol updated to 3.5.1 coinciding with the Kontrol MK3 keyboard firmware 2.0 update (now 2.0.6). For me, the only problem is that inserting an instance of Komplete Kontrol in Logic Pro does not integrate the Komplete Kontrol browser and Plug In on my MK3 S61. The DAW and transport controls still work. The Browser button is greyed out and not available. Clicking on the Plug-In button loads the new generic screen for Logic Pro's Smart Controls (first button on the left, top of the screen) or the direct plug-in controls (second button, top of the screen). This Plug-In screen displays the new pages for non-NKS plugin controls since the firmware 2.0 update. The displays and Browser/Plug-In buttons for NKS instruments, like Komplete Kontrol, are supposed to supersede the new generic controls. However, in this case, that process is failing for some reason.
For me, the fix is to close Logic Pro, trash Apple's Logic Pro preference file:
Macintosh HD/Users/Username/Library/Preferences/com.apple.logic.pro.cs
… and then restart Logic Pro. However, this only works for a couple of Logic Pro's sessions, and then it breaks again. It is obviously a relatively minor annoyance bug more than anything. I'm hoping the team can get this figured out soon. I'm putting this here mainly as a heads up to other Logic Pro users that may continue to experience the same error, even after running through all the tips above.
Interestingly I do not have the same problem with Kontakt 8; it integrates fine with my MK3 S61. Hopefully, whatever makes it work for Kontakt can be used to fix Komplete Kontrol.