Hello Luis,
KDS itself doesn't support processor expert for K66. but KSDK 1.3 includes processor expert support for k66.
Thus user need install KSDK1.3.
See the following link:
http://www.nxp.com/products/wireless-connectivity/2.4-ghz-wireless-solutions/ieee-802.15.4-plus-ble/...
and navigate to the Kinetis SDK 1.3 Mainline download link:

with SDK2 released, we don't encourage user use proessor expert +k66.
If you use KDS with K66, Our recommendation is SDK2.x
Have a great day,
Jennie Zhang
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