Hi Ed – it’s possible you’ve misunderstood something. The number of channels in the Endpoint setup are quite simply the number of MIDI channels you have asked for and they are always listed in ascending order, irrespective of whether they are allocated to an instrument or not. This in turn looks to your instrument/channel set up in the main Play window to see what you are actually using. Thus, if you have set channel 8 to Cello but have not assigned an instrument to the others, then they will be simply left blank. Below is a simple example as illustration.
Here I have asked for 4 channels but the viola in the project does not have a VST allocated so it is thus blank in the list You just need to make sure the instruments are set up in Play windows with the correct VST and channel. The Endpoint window fills in the instruments according to what’s in the Play window. In the VST interface-- Kontakt in your case – it doesn’t matter what instruments are there or what order but of course what you actually want to use in your project must must match the VST and channel set in the Play window, otherwise you get the wrong instrument or none at all. Don’t worry about the actual labels, it really doesn’t matter whether abbreviations used in the mixer are different from Kontakt, the only thing to worry about is making sure the channel matches which appears to be correct for your cello. Most VST’s work the same and it would be a mistake to think there is something different with Kontakt.
If you’re using Halion for the other instruments, then you must set them to the Halion VST with correct channel in the Play window. They will then show up in the Endpoint setup. The only thing you actually edit in the endpoint is the Expression Map to be used and optionally how many channels you want shown in the mixture.