Hi, it is often reported as you say, ‘those instruments do not work’, but in actual use,
they will work in NI’s Kontakt demo mode.
From Native Instruments K6 Player FAQ,
“Instruments that are not made for KONTAKT 6 PLAYER require the full version of KONTAKT 6 to run, but can be used for 15 minutes at a time in demo mode and without the ability to save your work.”
The statement (and others in past years) is a bit grammatically inconsistant, leading to lots of confusion. Their demo mode also leads to lots of purchases. Also, it’s 30 minutes on their other products. Player content itself has no time limits, but the timer is invoked from player versions when any commercial assets are loaded. All in all, I think it’s the best demo arrangement out there. And it’s enabled me purchase several items with confidence after a thorough testing. (There are various version inconsistancies when dealing with older libraries and various Kontakt versions, but I recently purchase a lib that was ten years old, and it seems to work fine)