At one time all 3 were under VST Instruments. But now Plugin Manager puts the 8 & 16 output versions under VST Audio Effects.
 
If I go to their Properties and check "Configure as synth" and "Force Stereo" and rescan they're all under VST Instruments but with (32 bit) attached to their names. And under "Details" they still have Outputs: 0; Is Synth: No, which causes them to fail when trying to insert them.
 
Doing this also deletes the 64 output version from the Insert Synth menu even though it's still listed in Plugin Manager.
 
What's going on?

VSTs are classified as Instruments if they can respond to MIDI, otherwise they're classified as Effects.
 
ALL of my Kontact plugs are instruments.
 
What is the file name of one of yours that's being classified as an effect?

I'm using Sonar Plat x64 and have filtered out all my NI 32 bit plugins.
So maybe if there is an issue I'm not seeing it.
My 64bit Kontakt plugs are behaving.
 

Kontakt 5 8out renamed kontakt 5.5-1.dll
Kontakt 5 16out renamed kontakt 5.5-2.dll
 
They are in the 64bit Program Files Cakewalk VST folder with Kontakt 5 64out renamed kontakt 5.5-3.dll
 
Maybe the install went bad. I'll reinstall them today.

>with (32 bit) attached to their names. 
That would indicate that they are 32 bit plugins.
Sounds like you might have some other issues like misnamed plugs or 64/32 mixing.
Check the registry* or use some other tools (like SaviHost) to verify what you're working with.
 
*For Sonar Plat x64 
HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR\Cakewalk VST X64\Inventory
 
 

Thanks. I'm going to uninstall everything, clear the registry and start over.

I find life easier by not using system folders like \Program Files to store my plugins.
I never have Admin issues or problems moving, backing up or restoring my plugins.
Well almost never, some plugins are a pain regardless of what you do.

I found over 10,000 entries for Kontakt 5 in the registry after I uninstalled it (WHAAAA...!), so there's no way I'm going to delete  them all one by one. After searching for and fooling with 1/2 a doz reg uts, I found a free one (RegSeeker 4) that located and deleted them all for me.
 
The others either want money and wouldn't delete, or have you, once again, delete each entry one by one.

Did you move/rename the 64bit Kontact .dll files? If so NI will no longer recognise them. There is a tool to fix this. See here 

Thanks, but I uninstalled Kontakt kompletely and wanted absolutely no trace of it left anywhere... so I can reinstall it clean and hopefully resolve the issue of it not installing properly the first time.