I use Noteworthy Composer for my music, and Garritan Studio works fine with it, but I can't use Jazz & Big Band in Garritan Studio, nor can I use the Kontakt Player with NC.
Is there anything I can do?
Yes, you should be able to use JABB (KP2) and NC together, but you'll need a set of virtual midi cables to allow the two to communicate. Midi-Yoke does a good job. Install MIDI Yoke, then select the first port's channels as your outputs from NC. On the KP2 standalone that JABB runs in, go to the steup window and select that Midi Yoke Port as an input option. In the standalone, the port letters correspond to the order of the ports enabled, so the first port from the top enabled is A, the second is B, and so on.